US20020002621A1 - Multiple network connections from a single ppp link with partial network address translation - Google Patents

Multiple network connections from a single ppp link with partial network address translation Download PDF

Info

Publication number
US20020002621A1
US20020002621A1 US09/186,214 US18621498A US2002002621A1 US 20020002621 A1 US20020002621 A1 US 20020002621A1 US 18621498 A US18621498 A US 18621498A US 2002002621 A1 US2002002621 A1 US 2002002621A1
Authority
US
United States
Prior art keywords
network
packet
network address
user
destination
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US09/186,214
Other versions
US6381646B2 (en
Inventor
Shujin Zhang
Jane Jiaying Jin
Jie Chu
Maria Dos Santos
Shuxian Lou
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cisco Technology Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US09/186,214 priority Critical patent/US6381646B2/en
Assigned to CISCO TECHNOLGY, INC. reassignment CISCO TECHNOLGY, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CHU, Jie, DOS SANTOS, MARIA ALICE, JIN, JANE JIAYING, LOU, SHUXIAN, ZHANG, SHUJIN
Publication of US20020002621A1 publication Critical patent/US20020002621A1/en
Application granted granted Critical
Publication of US6381646B2 publication Critical patent/US6381646B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/40—Network security protocols
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/14—Multichannel or multilink protocols

Definitions

  • the present invention relates to the field of computer networks. More particularly, the present invention relates to managing multiple network connections from a single PPP link with partial network address translation.
  • the Point-to-Point protocol is a data link protocol that provides dial up access over analog or digital transmission lines.
  • PPP provides many advanced features, including error detection, support of multiple protocols, negotiation of IP addresses at connection time, and authentication.
  • the second is a link control protocol for bringing lines up, testing them, negotiating options, and bringing them down again when they are no longer needed. This is known as the Link Control Protocol (LCP).
  • LCP Link Control Protocol
  • the third is a way to negotiate network layer options in a way independent of the network layer protocol to be used. Thus, the method chosen may have a different Network Control Protocol (NCP) for each network layer supported.
  • NCP Network Control Protocol
  • PPP is commonly used as the data link protocol between a user and an Internet Service Provider (ISP) or access point. This is usually accomplished through the following method.
  • the personal computer of the user is instructed to call the ISP through a modem .
  • the ISP's modem receives the call and establishes a physical connection, the personal computer sends a series of LCP packets in the payload field of one or more PPP frames. These packets, and their responses, comprise the negotiation of the session, and set the PPP parameters to be used during the session.
  • NCP packets are sent to configure the network layer.
  • the personal computer wants to run a TCP/IP protocol stack, so it needs an IP address.
  • the NCP for IP may then be used to assign an IP address to the user (dynamic assignment of IP addresses is now common for dial-up users).
  • the personal computer has become an Internet host and may send and receive IP packets, just as a hardwired host could.
  • NCP is used to tear down the network layer connection and free the IP address.
  • the LCP is then used to shut down the data link layer connection. Finally, the personal computer hangs up the modem, releasing the physical layer connection.
  • intranets have been rising in popularity, especially with large companies.
  • An intranet is an internal network that serves only a specific type of person (such as employees of a corporation, or students at a school).
  • the intranet is usually not accessible to the general public.
  • Intranets have become popular mainly because they allow for much more productive communication between users within the network, TABLE 1 Name Direction Description Configure-request I ⁇ R List of proposed options and values Configure-ack I ⁇ R All options are accepted Configure-nak I ⁇ R Some options are not accepted Configure-reject I ⁇ R Some options are not negotiable Terminate-request I ⁇ R Request to shut down the line Terminate-ack I ⁇ R OK to shut down the line Code-reject I ⁇ R Unknown request received Protocol-reject I ⁇ R Unknown protocol received Echo-request I ⁇ R Please send this frame back Echo-reply I ⁇ R Here is the frame back Discard-request I ⁇ R Discard this frame (for testing)
  • FIG. 1 is a block diagram depicting the typical connection to an intranet.
  • Personal computer 10 connects through a link 12 to an Internet service provider (ISP) or access point (AP) 14 .
  • ISP Internet service provider
  • AP access point
  • the ISP or AP 14 then connects through link 16 to the Intranet 18 .
  • FIG. 2 is a block diagram illustrating a connection to the Internet 62 through an intranet 58 .
  • a user at PC 50 maintains a PPP connection 52 to ISP 54 , which is connected to the intranet 58 .
  • Intranet 58 is then connected through link 60 to the Internet 62 .
  • the drawback of this solution is that the traffic from the user at PC 50 to the Internet 62 passes through the intranet 58 . This increases the traffic traveling through the intranet 58 and poses a security risk to the information sent via the intranet 58 .
  • PPP Planar Packet Control Protocol
  • NAT Network address translation
  • IP Internet Protocol
  • Gateway which is a device that acts as an interface between the ISP and the intranet or Internet.
  • Network address translation provides two main advantages. First, it adds security to the LAN or intranet, as it acts as a type of firewall, preventing users from outside the LAN or intranet from determining the internal network addressing scheme of the LAN or intranet. Second, it saves network addresses. With the ever growing popularity of the Internet and computer networks, a major issue is the availability of IP addresses. A standard IP address is 32 bytes in length, providing a total of 232 possible IP addresses. Those of ordinary skill in the art will readily recognize that not all of these possible IP addresses are available due to administrative expediencies, such as reserving blocks of IP addresses for future use. Network address translation saves IP addresses by allowing the ISP to use IP addresses internally that may be used by other networks on the Internet because there is no possibility of conflict.
  • IPSec IP security protocol
  • a primary PPP connection is established between a user and a first network.
  • a first real network address for the user is then received, the first real network address assigned by the first network.
  • the gateway may establish a secondary network session between a gateway and a second network, receiving a second real network address assigned by the second network. Additional network connections may be added as secondary network sessions.
  • Network address translation is then performed on packets traveling between the user and any of the secondary network sessions, but not on packets traveling between the user and the primary PPP connection. This allows for connection to multiple networks without disturbing the primary PPP session and also allows for the utilization of applications which may not be used with network address translation on the primary PPP session.
  • FIG. 1 is a block diagram depicting a typical connection to an intranet.
  • FIG. 2 is a block diagram illustrating a connection to the Internet through an intranet.
  • FIG. 3 is a diagram illustrating the use of a gateway to couple multiple networks according to a presently preferred embodiment of the present invention.
  • FIG. 4 is a flow diagram illustrating a method for establishing multiple network connections for a user having a PPP connection to a gateway according to presently preferred embodiment of the present invention.
  • FIG. 5 is a block diagram illustrating a network gateway for use in a system having a user with a PPP connection to a gateway.
  • FIG. 6 is a block diagram illustrating multiple network connections from a single PPP connection as they would appear after the steps depicted in FIG. 4 were executed in accordance with a presently preferred embodiment of the present invention.
  • FIG. 7 is a flow diagram illustrating a method for outgoing communications routing in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the present invention.
  • FIG. 8 is a diagram of a packet in accordance with the IP protocol.
  • FIG. 9 is a flow diagram illustrating a method for incoming communications routing of in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the present invention.
  • FIG. 10 is a block diagram illustrating a network in accordance with another embodiment of the present invention.
  • the components, process steps, and/or data structures are implemented using a gateway device.
  • Different implementations may be used and may include other types of operating systems, computing platforms, computer programs, and/or general purpose machines.
  • devices of a less general purpose nature such as hardwired devices, devices relying on FPGA or ASIC technology, or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herewith.
  • a method for making multiple network connections with only partial network address translation is provided. This method may be executed by a gateway.
  • a gateway is a device which performs protocol conversion between different types of networks or applications.
  • the term gateway is not meant to be limited to a single type of device, as any device, hardware or software, that may act as a bridge between the user and the networks may be considered a gateway for purposes of this application.
  • FIG. 3 is a diagram illustrating the use of a gateway to couple multiple networks.
  • Computer 80 connects to gateway 82 through a modem 84 , while computers 86 a and 86 b couple to a hub 88 , then through modem 90 to gateway 82 .
  • Gateway 82 may then interface computers 80 , 86 a , and 86 b to multiple networks. These may include a first corporate intranet 92 , a second corporate intranet 94 , and the Internet 96 .
  • FIG. 4 is a flow diagram illustrating a method for establishing multiple network connections for a user having a PPP connection to a gateway according to presently preferred embodiment of the invention.
  • a PPP session is established between the user and a first network. This may have been performed in two separate steps. First, the user may have established a PPP session with the gateway. Second, the gateway may have then established a PPP session with the first network, thus extending the endpoint of the PPP session established by the user to the first network. This is known as a primary session because it is one contiguous session with the endpoints being the user and the first network.
  • a first real network address is received for the user. This first real network address is assigned by the first network.
  • this network will be the dominant one for the user, meaning that this network is the one used the most by the user.
  • this connection will likely be the one that is used to connect to the intranet of the company of which the user is employed, since it is likely that more traffic will travel between the user and the first network than the user and the second network.
  • this primary session be linked to the dominant network or that the dominant network be a specific network.
  • the gateway may establish a secondary network session between the gateway and a second network. Unlike the primary session, there is no requirement that this session be a PPP session (although it may be). Therefore, this session may comply with any network protocol.
  • a second real network address for the user is received, the second real network address assigned by the second network. Since this is a secondary session, network address translation will be utilized. This may or may not require an action to be taken by the gateway at this point. Some forms of network address translation require that a NAT table be maintained.
  • the gateway may place the second real network address in a NAT table in an entry corresponding to the first real network address.
  • the first real network address may be used as the local address.
  • Some forms of network address translation involve simply applying the network address translation scheme to each packet as it is received. In such instances, no steps need to be taken by the gateway until a packet is received.
  • FIG. 5 is a block diagram illustrating a network gateway for use in a system having a user with a PPP connection to the gateway.
  • User 130 has a PPP connection to gateway 132 .
  • the gateway 132 then contains many parts that interface the user 130 to multiple networks.
  • a request receiver 134 receives a first PPP connection request from the user.
  • An LCP negotiator 136 negotiates LCP options between the user and a first network.
  • a network session initiator 138 establishes a primary PPP session between the user and a first network while a network address receiver 140 receives a first real network address for the user, the first real network address assigned by the first network.
  • the request receiver 134 further receives a second PPP connection request from the user.
  • the LCP negotiator 136 further negotiates LCP options between the user and a second network.
  • the network session initiator 138 further establishes a secondary network session between the gateway and a second network and the network address receiver 140 further receives a second real network address for the user, the second real network address assigned by the second network.
  • the gateway may also contain a network address translation table 142 having multiple entries 144 .
  • a NAT table storer 146 may then store the second real network address in the network address translation table 132 in an entry 144 corresponding to the first real network address.
  • FIG. 6 is a block diagram illustrating multiple network connections from a single PPP connection as they would appear after the steps depicted in FIG. 4 were executed.
  • PC 150 maintains the PPP connection to the ISP 154 , which may contain the gateway.
  • Primary PPP session 156 links the PC to the first network 158 , while secondary network connection 160 connects the gateway to the second network.
  • the gateway may configure more than one secondary network sessions should the user so desire. These additional secondary network sessions are created in a similar fashion to the original secondary network session.
  • Tunneling allows two hosts on the same type of network to communicate even though there may be different types of network in between. Tunneling is accomplished by encapsulating packets sent from a first type of network within packets of a type compatible with a second type of network for the duration of the packet's journey through the second type of network. Then, the outer packet is stripped off (and possibly some demultiplexing takes place) when the packet reaches the first type of network again.
  • Layer Two Tunneling Protocol is a specific tunneling protocol that acts as an extension to the PPP protocol to allow ISPs to operate virtual private networks. L2TP or any other tunneling protocol may be used when establishing the primary and secondary sessions.
  • FIG. 7 is a flow diagram illustrating a method for outgoing communications routing in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the invention.
  • FIG. 8 is a diagram illustrating a packet in accordance with the IP protocol. Normally, there will be a destination network address field 232 within the packet 230 . The destination network address may then be extracted from this field. Then the address may be compared with a routing table. This routing table may be maintained by the gateway or a router. The routing table contains a list of addresses and the corresponding networks to which packets sent to that address should be routed. This allows the gateway to forward the packets to the correct network. In many cases, routing the packets to either network will allow the packet to arrive at its destination.
  • the routing table may indicate the network that will provide for the shortest travel time for the packet, in order to save the user some time.
  • it will not be clear to which network to send the packet (indicated by the fact that there is no entry for the address in the routing table). In these eases, a default network will be established to which to send packets.
  • the packet is directly forwarded to the first network. If, however, the destination network is the second network, then at step 206 network address translation is performed (perhaps by applying a network address translation mapping scheme to the packet or perhaps by looking up the destination address in a NAT table) to modify the source network address. At step 208 , the packet is then forwarded to the second network.
  • a similar scheme may be utilized when there are more than two simultaneous network connections, with NAT being performed on each network connection but the primary one.
  • FIG. 9 is a flow diagram illustrating a method for incoming communications routing of in a system in which a user is connected to a first network and a second network.
  • a packet is received from the first network or the second network.
  • the packet is examined to determine the source network. Referring back to FIG. 8, like the destination address, the source address of the packet is generally located within a field 234 in the packet 230 .
  • the packet is simply forwarded to the user at step 254 . If, however, the source is the second network (or any other secondary sessions), network address translation is performed on the packet at step 256 . Then the packet is forwarded to the user at step 258 .
  • FIG. 10 is a block diagram illustrating a network gateway according to another embodiment of the present invention. The components of this gateway may be combined with the gateway depicted in FIG. 5 for use as one complete gateway.
  • a packet receiver 300 receives a packet sent by the user.
  • Packet examiner 302 examines the packet to determine if its destination is the first network or the second network.
  • Packet forwarder 304 forwards the packet to the first network if the packet indicates that its destination is the first network.
  • Network address translator 306 performs network address translation on the packet if the packet indicates that its destination is the second network.
  • the packet forwarder 304 further forwards the translated packet to the second network if the packet indicates that its destination is the second network.
  • a NAT table storer 308 may be provided which stores the second real network address in a network address translation table in an entry corresponding to the first real network address.
  • Packet examiner 302 further includes an address extractor 310 , which extracts a destination network address from the packet, a routing table searcher 312 , which looks up the destination network address in a routing table, and a network determiner 314 , which determines that said destination is the first network or the second network based upon the listing for the destination network address in the routing table.
  • the packet receiver 300 receives a second packet, the second packet sent from the first network or the second network.
  • the packet examiner 302 further examines the second packet to determine if its source is the first network or the second network.
  • the network address translator 304 performs network address translation on the second packet if the second packet indicates that its source is the second network.
  • the packet forwarder 306 further forwards the second packet to the user.
  • the packet examiner 302 may further contain an address extractor 308 , which extracts a destination network address from the packet, a routing table searcher 310 , which looks up the destination network address in a routing table, and a network determiner 312 , which determines that the destination is the first network or the second network based upon the listing for the destination network in the routing table.
  • the network determiner 312 may further determine that the destination is the first network or second network based upon a default setting if the destination network address is not listed in the routing table.
  • the packet receiver 300 may further receive a second packet, the second packet sent from said first network or said second network,
  • the packet examiner 302 may further examine said second packet to determine if its source is said first network or said second network.
  • the network address translator 306 may further perform network address translation on said second packet if said second packet indicates that its source is said second network.
  • the packet forwarder 304 may further forward said second packet to the user.
  • the present invention allows for the simultaneous connection to two or more network s from only one single PPP connection. It also allows for networks to be added at the time the user requests connection, such that the networks do not need to be preconfigured.
  • the primary PPP connection to the first network is maintained without using network address translation, thus allowing for the use of applications that affect the header of the packets, thus providing more security when programs like IPSec are used.
  • An additional increase in security is provided in that traffic to networks travel directly to the gateway rather than through one of the other simultaneously connected networks.

Abstract

Multiple simultaneous network connections from a single PPP connection may be accomplished. A primary PPP connection is established between a user and a first network. A first real network address for the user is then received, the first real network address assigned by the first network. Then, the gateway may establish a secondary network session between a gateway and a second network, receiving a second real network address assigned by the second network. Additional network connections may be added as secondary network sessions. Network address translation is then performed on packets traveling between the user and any of the secondary network sessions, but not on packets traveling between the user and the primary PPP connection. This allows for connection to multiple networks without disturbing the primary PPP session and also allows for the utilization of applications which may not be used with network address translation on the primary PPP session.

Description

    BACKGROUND OF THE INVENTION
  • 1. Field Of the Invention [0001]
  • The present invention relates to the field of computer networks. More particularly, the present invention relates to managing multiple network connections from a single PPP link with partial network address translation. [0002]
  • 2. The Background [0003]
  • The Point-to-Point protocol (PPP) is a data link protocol that provides dial up access over analog or digital transmission lines. PPP provides many advanced features, including error detection, support of multiple protocols, negotiation of IP addresses at connection time, and authentication. There are three main features of PPP. The first is that it provides a framing method to delineate the end of one frame and the beginning of the next one, in order to handle error detection. The second is a link control protocol for bringing lines up, testing them, negotiating options, and bringing them down again when they are no longer needed. This is known as the Link Control Protocol (LCP). The third is a way to negotiate network layer options in a way independent of the network layer protocol to be used. Thus, the method chosen may have a different Network Control Protocol (NCP) for each network layer supported. [0004]
  • PPP is commonly used as the data link protocol between a user and an Internet Service Provider (ISP) or access point. This is usually accomplished through the following method. The personal computer of the user is instructed to call the ISP through a modem . After the ISP's modem receives the call and establishes a physical connection, the personal computer sends a series of LCP packets in the payload field of one or more PPP frames. These packets, and their responses, comprise the negotiation of the session, and set the PPP parameters to be used during the session. [0005]
  • Once the negotiation is complete, a series of NCP packets are sent to configure the network layer. Typically, the personal computer wants to run a TCP/IP protocol stack, so it needs an IP address. The NCP for IP may then be used to assign an IP address to the user (dynamic assignment of IP addresses is now common for dial-up users). At this point, the personal computer has become an Internet host and may send and receive IP packets, just as a hardwired host could. When the user has finished, NCP is used to tear down the network layer connection and free the IP address. The LCP is then used to shut down the data link layer connection. Finally, the personal computer hangs up the modem, releasing the physical layer connection. [0006]
  • There are currently eleven types of LCP packets. These types are illustrated in Table 1 below, along with the direction in which they travel (from Initiator (I) to responder (R) or vice-versa) and their description. [0007]
  • In recent years, “intranets” have been rising in popularity, especially with large companies. An intranet is an internal network that serves only a specific type of person (such as employees of a corporation, or students at a school). The intranet is usually not accessible to the general public. Intranets have become popular mainly because they allow for much more productive communication between users within the network, [0008]
    TABLE 1
    Name Direction Description
    Configure-request I → R List of proposed options and values
    Configure-ack I ← R All options are accepted
    Configure-nak I ← R Some options are not accepted
    Configure-reject I ← R Some options are not negotiable
    Terminate-request I → R Request to shut down the line
    Terminate-ack I ← R OK to shut down the line
    Code-reject I ← R Unknown request received
    Protocol-reject I ← R Unknown protocol received
    Echo-request I → R Please send this frame back
    Echo-reply I ← R Here is the frame back
    Discard-request I → R Discard this frame (for testing)
  • even when the users are dispersed over a wide geographic area (such as in multi-national corporations). [0009]
  • FIG. 1 is a block diagram depicting the typical connection to an intranet. [0010] Personal computer 10 connects through a link 12 to an Internet service provider (ISP) or access point (AP)14. The ISP or AP 14 then connects through link 16 to the Intranet 18.
  • Many entities that maintain intranets, however, have also wanted to offer users access to the Internet or to other intranets as well. There were, however, a limited number of ways that this could be accomplished. The first, and most simple, way would be for the user to first terminate the existing PPP connection between the PC [0011] 10 and the ISP or access point 24. Then the user could log into a second intranet or to the Internet. The major drawbacks of this solution are obvious. It does not allow for simultaneous connection to two intranets, or to one intranet and the Internet, thus limiting the productivity of the user. Additionally, it requires termination of the PPP link between the PC and the ISP, thus using up valuable time on the user's end, as he has to re-initiate a connection process.
  • The second way an entity could offer access to a second intranet or to the Internet is to have a preconfigured connection from the intranet to the second intranet or Internet, such that communications between the user and the second intranet or Internet pass through the intranet. FIG. 2 is a block diagram illustrating a connection to the Internet [0012] 62 through an intranet 58. A user at PC 50 maintains a PPP connection 52 to ISP 54, which is connected to the intranet 58. Intranet 58 is then connected through link 60 to the Internet 62. The drawback of this solution is that the traffic from the user at PC 50 to the Internet 62 passes through the intranet 58. This increases the traffic traveling through the intranet 58 and poses a security risk to the information sent via the intranet 58.
  • One major drawback of PPP, therefore, is that it is designed as a point to point protocol, meaning that it is designed for use between two endpoints. Therefore, it is currently not possible for a user to connect to two independent endpoints simultaneously (such as an intranet and the Internet, or to two independent intranets) using a single PPP link. [0013]
  • What is needed is a method by which a user may connect to two independent endpoints simultaneously using a single PPP link. [0014]
  • Additionally, when a system is designed in which data is to be sent to the Internet, Network address translation (NAT) is sometimes used. NAT is an Internet standard that enables a local-area network (LAN), intranet, or ISP to use one set of network addresses for internal traffic and a separate set of network addresses for external traffic. Network addresses are generally Internet Protocol (IP) addresses, but there are many other possible network addresses as well. At the ISP level, there is normally a gateway, which is a device that acts as an interface between the ISP and the intranet or Internet. When network address translation is used, the Gateway will act to convert the destination addresses of incoming and outgoing packets so that traffic is directed to the correct address. [0015]
  • Network address translation provides two main advantages. First, it adds security to the LAN or intranet, as it acts as a type of firewall, preventing users from outside the LAN or intranet from determining the internal network addressing scheme of the LAN or intranet. Second, it saves network addresses. With the ever growing popularity of the Internet and computer networks, a major issue is the availability of IP addresses. A standard IP address is 32 bytes in length, providing a total of 232 possible IP addresses. Those of ordinary skill in the art will readily recognize that not all of these possible IP addresses are available due to administrative expediencies, such as reserving blocks of IP addresses for future use. Network address translation saves IP addresses by allowing the ISP to use IP addresses internally that may be used by other networks on the Internet because there is no possibility of conflict. [0016]
  • There are several drawbacks, however, to using NAT. The first is that it is slightly more inefficient than not using NAT, since each packet must then be examined by a gateway or router and the translation performed. Of greater importance, however, is the fact that there are several kinds of IP applications which are incompatible with a system in which NAT is being used. These include any type of application which encrypts the header of the IP packet. One example of this is the IP security protocol (IPSec). IPSec encrypts the entire IP packet (header included) and only allows decryption at an endpoint with access privileges to the header. Since the header is encrypted, NAT will alter the packet so that the receiver of the packet will not accept the packet. [0017]
  • What is needed is a solution which overcomes these drawbacks. [0018]
    • SUMMARY OF THE INVENTION
  • Multiple simultaneous network connections from a single PPP connection may be accomplished. A primary PPP connection is established between a user and a first network. A first real network address for the user is then received, the first real network address assigned by the first network. Then, the gateway may establish a secondary network session between a gateway and a second network, receiving a second real network address assigned by the second network. Additional network connections may be added as secondary network sessions. Network address translation is then performed on packets traveling between the user and any of the secondary network sessions, but not on packets traveling between the user and the primary PPP connection. This allows for connection to multiple networks without disturbing the primary PPP session and also allows for the utilization of applications which may not be used with network address translation on the primary PPP session.[0019]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a block diagram depicting a typical connection to an intranet. [0020]
  • FIG. 2 is a block diagram illustrating a connection to the Internet through an intranet. [0021]
  • FIG. 3 is a diagram illustrating the use of a gateway to couple multiple networks according to a presently preferred embodiment of the present invention. [0022]
  • FIG. 4 is a flow diagram illustrating a method for establishing multiple network connections for a user having a PPP connection to a gateway according to presently preferred embodiment of the present invention. [0023]
  • FIG. 5 is a block diagram illustrating a network gateway for use in a system having a user with a PPP connection to a gateway. [0024]
  • FIG. 6 is a block diagram illustrating multiple network connections from a single PPP connection as they would appear after the steps depicted in FIG. 4 were executed in accordance with a presently preferred embodiment of the present invention. [0025]
  • FIG. 7 is a flow diagram illustrating a method for outgoing communications routing in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the present invention. [0026]
  • FIG. 8 is a diagram of a packet in accordance with the IP protocol. [0027]
  • FIG. 9 is a flow diagram illustrating a method for incoming communications routing of in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the present invention. [0028]
  • FIG. 10 is a block diagram illustrating a network in accordance with another embodiment of the present invention. [0029]
    • DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
  • Those of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons. [0030]
  • In accordance with a presently preferred embodiment of the present invention, the components, process steps, and/or data structures are implemented using a gateway device. Different implementations may be used and may include other types of operating systems, computing platforms, computer programs, and/or general purpose machines. In addition, those of ordinary skill in the art will readily recognize that devices of a less general purpose nature, such as hardwired devices, devices relying on FPGA or ASIC technology, or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herewith. [0031]
  • A method for making multiple network connections with only partial network address translation is provided. This method may be executed by a gateway. A gateway is a device which performs protocol conversion between different types of networks or applications. The term gateway is not meant to be limited to a single type of device, as any device, hardware or software, that may act as a bridge between the user and the networks may be considered a gateway for purposes of this application. FIG. 3 is a diagram illustrating the use of a gateway to couple multiple networks. Computer [0032] 80 connects to gateway 82 through a modem 84, while computers 86 a and 86 b couple to a hub 88, then through modem 90 to gateway 82. Gateway 82 may then interface computers 80, 86 a, and 86 b to multiple networks. These may include a first corporate intranet 92, a second corporate intranet 94, and the Internet 96.
  • FIG. 4 is a flow diagram illustrating a method for establishing multiple network connections for a user having a PPP connection to a gateway according to presently preferred embodiment of the invention. At [0033] step 100, a PPP session is established between the user and a first network. This may have been performed in two separate steps. First, the user may have established a PPP session with the gateway. Second, the gateway may have then established a PPP session with the first network, thus extending the endpoint of the PPP session established by the user to the first network. This is known as a primary session because it is one contiguous session with the endpoints being the user and the first network. At step 102, a first real network address is received for the user. This first real network address is assigned by the first network. Since this is the primary session, it is likely that this network will be the dominant one for the user, meaning that this network is the one used the most by the user. For example, this connection will likely be the one that is used to connect to the intranet of the company of which the user is employed, since it is likely that more traffic will travel between the user and the first network than the user and the second network. However, there is no requirement that this primary session be linked to the dominant network or that the dominant network be a specific network.
  • Since the primary session will most likely have the most amount of traffic traveling on it, network address translation will not be performed on packets traveling through this session. This allows the user to utilize the various Internet applications that could not be used with NAT, such as IPSec. The utilization of IPSec or similar security protocols may also allay some of the security concerns regarding access to information on the first network. [0034]
  • At some point during the session, the user may request connection to a second network. Therefore, at [0035] step 104, the gateway may establish a secondary network session between the gateway and a second network. Unlike the primary session, there is no requirement that this session be a PPP session (although it may be). Therefore, this session may comply with any network protocol. At step 106, a second real network address for the user is received, the second real network address assigned by the second network. Since this is a secondary session, network address translation will be utilized. This may or may not require an action to be taken by the gateway at this point. Some forms of network address translation require that a NAT table be maintained. In such instances, the gateway may place the second real network address in a NAT table in an entry corresponding to the first real network address. There is no need to assign a virtual network address, since the first real network address may be used as the local address. Some forms of network address translation involve simply applying the network address translation scheme to each packet as it is received. In such instances, no steps need to be taken by the gateway until a packet is received.
  • FIG. 5 is a block diagram illustrating a network gateway for use in a system having a user with a PPP connection to the gateway. [0036] User 130 has a PPP connection to gateway 132. The gateway 132 then contains many parts that interface the user 130 to multiple networks. A request receiver 134 receives a first PPP connection request from the user. An LCP negotiator 136 negotiates LCP options between the user and a first network. A network session initiator 138 establishes a primary PPP session between the user and a first network while a network address receiver 140 receives a first real network address for the user, the first real network address assigned by the first network. The request receiver 134 further receives a second PPP connection request from the user. The LCP negotiator 136 further negotiates LCP options between the user and a second network. The network session initiator 138 further establishes a secondary network session between the gateway and a second network and the network address receiver 140 further receives a second real network address for the user, the second real network address assigned by the second network.
  • The gateway may also contain a network address translation table [0037] 142 having multiple entries 144. A NAT table storer 146 may then store the second real network address in the network address translation table 132 in an entry 144 corresponding to the first real network address.
  • FIG. 6 is a block diagram illustrating multiple network connections from a single PPP connection as they would appear after the steps depicted in FIG. 4 were executed. [0038] PC 150 maintains the PPP connection to the ISP 154, which may contain the gateway. Primary PPP session 156 links the PC to the first network 158, while secondary network connection 160 connects the gateway to the second network.
  • The gateway may configure more than one secondary network sessions should the user so desire. These additional secondary network sessions are created in a similar fashion to the original secondary network session. [0039]
  • Additionally, “tunneling” may be utilized in the case where not all the links follow the same protocol. Tunneling allows two hosts on the same type of network to communicate even though there may be different types of network in between. Tunneling is accomplished by encapsulating packets sent from a first type of network within packets of a type compatible with a second type of network for the duration of the packet's journey through the second type of network. Then, the outer packet is stripped off (and possibly some demultiplexing takes place) when the packet reaches the first type of network again. Layer Two Tunneling Protocol (L2TP) is a specific tunneling protocol that acts as an extension to the PPP protocol to allow ISPs to operate virtual private networks. L2TP or any other tunneling protocol may be used when establishing the primary and secondary sessions. [0040]
  • FIG. 7 is a flow diagram illustrating a method for outgoing communications routing in a system in which a user is connected to a first network and a second network according to a presently preferred embodiment of the invention. [0041]
  • At [0042] step 200, a packet is received from the user. At step 202, the packet is examined to determine if its destination is the first network or the second network. FIG. 8 is a diagram illustrating a packet in accordance with the IP protocol. Normally, there will be a destination network address field 232 within the packet 230. The destination network address may then be extracted from this field. Then the address may be compared with a routing table. This routing table may be maintained by the gateway or a router. The routing table contains a list of addresses and the corresponding networks to which packets sent to that address should be routed. This allows the gateway to forward the packets to the correct network. In many cases, routing the packets to either network will allow the packet to arrive at its destination. In these cases, the routing table may indicate the network that will provide for the shortest travel time for the packet, in order to save the user some time. In yet other cases, it will not be clear to which network to send the packet (indicated by the fact that there is no entry for the address in the routing table). In these eases, a default network will be established to which to send packets.
  • Referring back to FIG. 7, if the destination network is the first network, then at [0043] step 204 the packet is directly forwarded to the first network. If, however, the destination network is the second network, then at step 206 network address translation is performed (perhaps by applying a network address translation mapping scheme to the packet or perhaps by looking up the destination address in a NAT table) to modify the source network address. At step 208, the packet is then forwarded to the second network. A similar scheme may be utilized when there are more than two simultaneous network connections, with NAT being performed on each network connection but the primary one.
  • Likewise, when a packet is received from the second network (or any other of the secondary sessions), then network address translation is performed. FIG. 9 is a flow diagram illustrating a method for incoming communications routing of in a system in which a user is connected to a first network and a second network. At [0044] step 250, a packet is received from the first network or the second network. At step 252, the packet is examined to determine the source network. Referring back to FIG. 8, like the destination address, the source address of the packet is generally located within a field 234 in the packet 230. Referring to FIG. 9, if the source is the first network, the packet is simply forwarded to the user at step 254. If, however, the source is the second network (or any other secondary sessions), network address translation is performed on the packet at step 256. Then the packet is forwarded to the user at step 258.
  • FIG. 10 is a block diagram illustrating a network gateway according to another embodiment of the present invention. The components of this gateway may be combined with the gateway depicted in FIG. 5 for use as one complete gateway. A [0045] packet receiver 300 receives a packet sent by the user. Packet examiner 302 examines the packet to determine if its destination is the first network or the second network. Packet forwarder 304 forwards the packet to the first network if the packet indicates that its destination is the first network. Network address translator 306 performs network address translation on the packet if the packet indicates that its destination is the second network. The packet forwarder 304 further forwards the translated packet to the second network if the packet indicates that its destination is the second network.
  • Additionally, a [0046] NAT table storer 308 may be provided which stores the second real network address in a network address translation table in an entry corresponding to the first real network address. Packet examiner 302 further includes an address extractor 310, which extracts a destination network address from the packet, a routing table searcher 312, which looks up the destination network address in a routing table, and a network determiner 314, which determines that said destination is the first network or the second network based upon the listing for the destination network address in the routing table.
  • For incoming packets, the [0047] packet receiver 300 receives a second packet, the second packet sent from the first network or the second network. The packet examiner 302 further examines the second packet to determine if its source is the first network or the second network. The network address translator 304 performs network address translation on the second packet if the second packet indicates that its source is the second network. The packet forwarder 306 further forwards the second packet to the user.
  • The [0048] packet examiner 302 may further contain an address extractor 308, which extracts a destination network address from the packet, a routing table searcher 310, which looks up the destination network address in a routing table, and a network determiner 312, which determines that the destination is the first network or the second network based upon the listing for the destination network in the routing table. The network determiner 312 may further determine that the destination is the first network or second network based upon a default setting if the destination network address is not listed in the routing table.
  • The [0049] packet receiver 300 may further receive a second packet, the second packet sent from said first network or said second network, The packet examiner 302 may further examine said second packet to determine if its source is said first network or said second network. The network address translator 306 may further perform network address translation on said second packet if said second packet indicates that its source is said second network. The packet forwarder 304 may further forward said second packet to the user.
  • The present invention allows for the simultaneous connection to two or more network s from only one single PPP connection. It also allows for networks to be added at the time the user requests connection, such that the networks do not need to be preconfigured. The primary PPP connection to the first network is maintained without using network address translation, thus allowing for the use of applications that affect the header of the packets, thus providing more security when programs like IPSec are used. An additional increase in security is provided in that traffic to networks travel directly to the gateway rather than through one of the other simultaneously connected networks. [0050]
  • While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. [0051]

Claims (95)

What is claimed is:
1. A method for establishing multiple network connections for a user having a PPP connection to a gateway, including the steps of:
establishing a primary PPP session between the user and a first network;
receiving a first real network address for said user, said first real network address assigned by said first network;
establishing a secondary network session between the gateway and a second network; and
receiving a second real network address for the user, said second real network address assigned by said second network.
2. The method of claim 1, further including the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
3. The method of claim 1, wherein said primary PPP session and said secondary network session are tunneling sessions.
4. The method of claim 3, wherein said primary PPP session and said secondary network session are L2TP sessions.
5. A method for establishing multiple network connections for a user having a PPP connection to a gateway, including the steps of:
receiving a first PPP connection request from the user;
negotiating LCP options between the user and a first network;
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
receiving a second PPP connection request from the user;
negotiating LCP options between the user and a second network;
establishing a secondary PPP session between the gateway and a second network; and
receiving a second real network address for the user, said second real network address assigned by said second network.
6. The method of claim 5, further including the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
7. The method of claim 5, wherein said primary PPP session and said secondary network session are tunneling sessions.
8. The method of claim 7, wherein said primary PPP session and said secondary network session are L2TP sessions.
9. A method for communications routing in a system in which a user is connected to a first network and a second network, the method including the steps of:
receiving a packet sent from the user;
examining said packet to determine if its destination is the first network or the second network;
forwarding said packet to the first network if said packet indicates that its destination is the first network;
performing network address translation on said packet if said packet indicates that its destination is the second network; and
forwarding said translated packet to the second network if said packet indicates that its destination is the second network.
10. The method of claim 9, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
11. The method of claim 9, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
12. The method of claim 9, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
looking up said source network address in said network address translation table.
13. The method of claim 9, further including the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
14. A method for network communications in a system having a user with a PPP connection to a gateway, including the steps of:
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
establishing a secondary network session between the gateway and a second network;
receiving a second real network address for the user, said second real network address assigned by said second network;
receiving a packet sent by the user;
examining said packet to determine if its destination is said first network or said second network;
forwarding said packet to the first network if said packet indicates that its destination is said first network;
performing network address translation on said packet if said packet indicates that its destination is said second network; and
forwarding said translated packet to said second network if said packet indicates that its destination is said second network.
15. The method of claim 14, further including the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
16. The method of claim 14, wherein said primary PPP session and said secondary network session are tunneling sessions.
17. The method of claim 16, wherein said primary PPP session and said secondary network session are L2TP sessions.
18. The method of claim 14, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
19. The method of claim 14, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
20. The method of claim 15, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
looking up said source network address in said network address translation table.
21. The method of claim 14, further including the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
22. A method for network communications in a system having a user with a PPP connection to a gateway, including the steps of:
receiving a first PPP connection request from the user;
negotiating LCP options between the user and a first network;
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
receiving a second PPP connection request from the user;
negotiating LCP options between the user and a second network;
establishing a secondary PPP session between the gateway and a second network;
receiving a second real network address for the user, said second real network address assigned by said second network;
receiving a packet sent by the user;
examining said packet to determine if its destination is said first network or said second network;
forwarding said packet to the first network if said packet indicates that its destination is said first network;
performing network address translation on said packet if said packet indicates that its destination is said second network; and
forwarding said translated packet to said second network if said packet indicates that its destination is said second network.
23. The method of claim 22, further including the steps of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
24. The method of claim 22, wherein said primary PPP session and said secondary network session are tunneling sessions.
25. The method of claim 24, wherein said primary PPP session and said secondary network session are L2TP sessions.
26. The method of claim 22, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
27. The method of claim 22, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
28. The method of claim 23, wherein said performing network address translation step includes the steps of: extracting a source network address from the packet; and looking up said source network address in said network address translation table.
29. The method of claim 22, further including the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
30. A network gateway for use in a system having a user with a PPP connection to the gateway, including:
a network session initiator adapted to establish a primary PPP session between the user and a first network;
a network address receiver adapted to receive a first real network address for the user, said first real network address assigned by said first network;
said network session initiator further adapted to establish a secondary network session between the gateway and a second network; and
said network address receiver further adapted to receive a second real network address for the user, said second real network address assigned by said second network.
31. The network gateway of claim 30, further including an NAT table storer adapted to store said second real network address in a network address translation table in an entry corresponding to said first real network address.
32. The network gateway of claim 30, wherein said primary PPP session and said secondary network session are tunneling sessions.
33. The network gateway of claim 32, wherein said primary PPP session and said secondary network session are L2TP sessions.
34. A network gateway for use in a system having a user with a PPP connection to the gateway, including:
a request receiver adapted to receive a first PPP connection request from the user;
an LCP negotiator adapted to negotiate LCP options between the user and a first network;
a network session initiator adapted to establish a primary PPP session between the user and a first network;
a network address receiver adapted to receive a first real network address for the user, said first real network address assigned by said first network;
said request receiver further adapted to receive a second PPP connection request from the user;
said LCP negotiator further adapted to negotiate LCP options between the user and a second network;
said network session initiator further adapted to establish a secondary PPP session between the user and a second network; and
said network address receiver further adapted to receive a second real network address for the user, said second real network address assigned by said second network.
35. The network gateway of claim 34, further including an NAT table storer adapted to store said second real network address in a network address translation table in an entry corresponding to said first real network address.
36. The network gateway of claim 34, wherein said primary PPP session and said secondary network sessions are tunneling sessions.
37. The network gateway of claim 36, wherein said primary PPP session and said secondary network session are L2TP sessions.
38. A network gateway including:
a packet receiver adapted to receive a packet sent from a user;
a packet examiner adapted to examine said packet to determine if its destination is a first network or a second network;
a packet forwarder adapted to forward said packet to the first network if said packet indicates that its destination is said first network;
a network address translator adapted to perform network address translation on said packet if said packet indicates that its destination is said second network; and
said packet forwarder further adapted to forward said translated packet to said second network if said packet indicates that its destination is said second network.
39. The network gateway of claim 38, wherein said packet examiner further includes:
an address extractor adapted to extract a destination network address from said packet;
a routing table searcher adapted to looks up said destination network address in a routing table;
a network determiner adapted to determine that said destination is said first network or said second network based upon the listing for the destination network address in the routing table; and
said network determiner further adapted to determine that said destination is said first network or said second network based on a default setting if said destination network address is not listed in said routing table.
40. The network gateway of claim 38, wherein said network address translator is further adapted to extract a source network address from the packet and apply a network address translation mapping scheme to said source network address.
41. The network gateway of claim 38, wherein said network address translator is further adapted to extract a source network address from the packet and look up said source network address in a network address translation table.
42. The network gateway of claim 38, wherein said packet receiver further is adapted to receive a second packet, said second packet sent from said first network or said second network, said packet examiner is further adapted to examine said second packet to determine if its source is said first network or said second network, said network address translator is further adapted to perform network address translation on said second packet if said second packet indicates that its source is said second network, and said packet forwarder is further adapted to forward said second packet to the user.
43. A network gateway for use in a system having a user with a PPP connection to the gateway, including:
a network session initiator adapted to establish a primary PPP session between the user and a first network;
a network address receiver adapted to receive a first real network address for the user, said first real network address assigned by said first network;
said network session initiator further establish a secondary network session between the user and a second network;
said network address receiver further receive a second real network address for the user, said second real network address assigned by said second network;
a packet receiver adapted to receive a packet sent by the user;
a packet examiner adapted to examine said packet to determine if its destination is said first network or said second network;
a packet forwarder adapted to forward said packet to the first network if said packet indicates that its destination is said first network;
a network address translator adapted to perform network address translation on said packet if said packet indicates that its destination is said second network; and
said packet forwarder further adapted to forward said translated packet to said second network if said packet indicates that its destination is said second network.
44. The network gateway of claim 43, further including an NAT table storer adapted to store said second real network address in a network address translation table in an entry corresponding to said first real network address.
45. The network gateway of claim 43, wherein said primary PPP session and said secondary network sessions are tunneling sessions.
46. The network gateway of claim 45, wherein said primary PPP session and said secondary network session are L2TP sessions.
47. The network gateway of claim 43, wherein said packet examiner further includes:
an address extractor adapted to extract a destination network address from said packet;
a routing table searcher adapted to look up said destination network address in a routing table;
a network determiner adapted to determine that said destination is said first network or said second network based upon the listing for the destination network address in the routing table; and
said network determiner further adapted to determine that said destination is said first network or said second network based on a default setting if said destination network address is not listed in said routing table.
48. The network gateway of claim 43, wherein said network address translator is further adapted to extract a source network address from the packet and apply a network address translation mapping scheme to said source network address.
49. The network gateway of claim 44, wherein said network address translator is further adapted to extract a source network address from the packet and look up said source network address in a network address translation table.
50. The network gateway of claim 43, wherein said packet receiver is further adapted to receive a second packet, said second packet sent from said first network or said second network, said packet examiner is further adapted to examine said second packet to determine if its source is said first network or said second network, said network address translator is further adapted to perform network address translation on said second packet if said second packet indicates that its source is said second network, and said packet forwarder is further adapted to forward said second packet to the user.
51. A network gateway for use in a system having a user with a PPP connection to the gateway, including:
a request receiver adapted to receive a first PPP connection request from the user;
an LCP negotiator adapted to negotiate LCP options between the user and a first network;
a PPP session initiator adapted to establishe a primary PPP session between a user and a first network;
a network address receiver adapted to receive a first real network address for the user, said first real network address assigned by said first network;
said request receiver further adapted to receive a second PPP connection request from the user;
said LCP negotiator further adapted to negotiate LCP options between the user and a second network;
said PPP session initiator further adapted to establish a secondary PPP session between the user and a second network;
said network address receiver further adapted to receive a second real network address for the user, said second real network address assigned by said second network;
a packet receiver adapted to receive a packet sent by the user;
a packet examiner adapted to examine said packet to determine if its destination is said first network or said second network;
a packet forwarder adapted to forward said packet to the first network if said packet indicates that its destination is said first network;
a network address translator adapted to perform network address translation on said packet if said packet indicates that its destination is said second network; and
said packet forwarder further adapted to forward said translated packet to the second network if said packet indicates that its destination is said second network.
52. The network gateway of claim 51, further including an NAT table storer adapted to store said second real network address in a network address translation table in an entry corresponding to said first real network address.
53. The network gateway of claim 51, wherein said primary PPP session and said secondary network sessions are tunneling sessions.
54. The network gateway of claim 53, wherein said primary PPP session and said secondary network session are L2TP sessions.
55. The network gateway of claim 51, wherein said packet examiner further includes:
an address extractor adapted to extract a destination network address from said packet;
a routing table searcher adapted to look up said destination network address in a routing table;
a network determiner adapted to determine that said destination is said first network or said second network based upon the listing for the destination network address in the routing table; and
said network determiner further adapted to determine that said destination is said first network or said second network based on a default setting if said destination network address is not listed in said routing table.
56. The network gateway of claim 51, wherein said network address translator is further adapted to extract a source network address from the packet and apply a network address translation mapping scheme to said source network address.
57. The network gateway of claim 52, wherein said network address translator is further adapted to extract a source network address from the packet and look up said source network address in a network address translation table.
58. The network gateway of claim 51, wherein said packet receiver is further adapted to receive a second packet, said second packet sent from said first network or said second network, said packet examiner is further adapted to examine said second packet to determine if its source is said first network or said second network, said network address translator is further adapted to perform network address translation on said second packet if said second packet indicates that its source is said second network, and said packet forwarder is further adapted to forward said second packet to the user.
59. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for establishing multiple network connections for a user having a PPP connection to a gateway, said method steps including the steps of:
establishing a primary PPP session between the user and a first network;
receiving a first real network address for said user, said first real network address assigned by said first network;
establishing a secondary network session between the gateway and a second network; and
receiving a second real network address for the user, said second real network address assigned by said second network.
60. The program storage device of claim 59, wherein the method further includes the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
61. The program storage device of claim 59, wherein said primary PPP session and said secondary network session are tunneling sessions.
62. The program storage device of claim 61, wherein said primary PPP session and said secondary network session are L2TP sessions.
63. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for establishing multiple network connections for a user having a PPP connection to a gateway, said method steps including the steps of:
receiving a first PPP connection request from the user;
negotiating LCP options between the user and a first network;
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
receiving a second PPP connection request from the user;
negotiating LCP options between the user and a second network;
establishing a secondary PPP session between the gateway and a second network; and
receiving a second real network address for the user, said second real network address assigned by said second network.
64. The program storage device of claim 63, wherein the method further includes the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
65. The program storage device of claim 63, wherein said primary PPP session and said secondary network session are tunneling sessions.
66. The program storage device of claim 65, wherein said primary PPP session and said secondary network session are L2TP sessions.
67. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for communications routing in a system in which a user is connected to a first network and a second network, the method including the steps of:
receiving a packet sent from the user;
examining said packet to determine if its destination is the first network or the second network;
forwarding said packet to the first network if said packet indicates that its destination is the first network;
performing network address translation on said packet if said packet indicates that its destination is the second network; and
forwarding said translated packet to the second network if said packet indicates that its destination is the second network.
68. The program storage device of claim 67, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
69. The program storage device of claim 67, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
70. The program storage device of claim 67, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
looking up said source network address in said network address translation table.
71. The program storage device of claim 67, wherein the method further includes the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
72. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for network communications in a system having a user with a PPP connection to a gateway, the method including the steps of:
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
establishing a secondary network session between the gateway and a second network;
receiving a second real network address for the user, said second real network address assigned by said second network;
receiving a packet sent by the user;
examining said packet to determine if its destination is said first network or said second network;
forwarding said packet to the first network if said packet indicates that its destination is said first network;
performing network address translation on said packet if said packet indicates that its destination is said second network; and
forwarding said translated packet to said second network if said packet indicates that its destination is said second network.
73. The program storage device of claim 72, wherein the method further includes the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
74. The program storage device of claim 72, wherein said primary PPP session and said secondary network session are tunneling sessions.
75. The program storage device of claim 74, wherein said primary PPP session and said secondary network session are L2TP sessions.
76. The program storage device of claim 73, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
77. The program storage device of claim 73, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
78. The program storage device of claim 74, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
looking up said source network address in said network address translation table.
79. The program storage device of claim 73, wherein the method further includes the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
80. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for network communications in a system having a user with a PPP connection to a gateway, the method including the steps of:
receiving a first PPP connection request from the user;
negotiating LCP options between the user and a first network;
establishing a primary PPP session between the user and a first network;
receiving a first real network address for the user, said first real network address assigned by said first network;
receiving a second PPP connection request from the user;
negotiating LCP options between the user and a second network;
establishing a secondary PPP session between the gateway and a second network;
receiving a second real network address for the user, said second real network address assigned by said second network;
receiving a packet sent by the user;
examining said packet to determine if its destination is said first network or said second network;
forwarding said packet to the first network if said packet indicates that its destination is said first network;
performing network address translation on said packet if said packet indicates that its destination is said second network; and
forwarding said translated packet to said second network if said packet indicates that its destination is said second network.
81. The program storage device of claim 80, wherein the method further includes the step of storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
82. The program storage device of claim 80, wherein said primary PPP session and said secondary network session are tunneling sessions.
83. The program storage device of claim 82, wherein said primary PPP session and said secondary network session are L2TP sessions.
84. The program storage device of claim 80, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
85. The program storage device of claim 80, wherein said performing network address translation step includes the steps of:
extracting a source network address from the packet; and
applying a network address translation mapping scheme to said source network address.
86. The program storage device of claim 81, wherein said performing network address translation step includes the steps of: extracting a source network address from the packet; and looking up said source network address in said network address translation table.
87. The program storage device of claim 81, wherein the method further includes the steps of:
receiving a second packet, said second packet sent from said first network or said second network;
examining said second packet to determine if its source is said first network or said second network;
performing network address translation on said second packet if said second packet indicates that its source is said second network; and
forwarding said second packet to the user.
88. A network gateway for network communications in a system having a user with a PPP connection to the gateway, including:
means for establishing a primary PPP session between the user and a first network;
means for receiving a first real network address for the user, said first real network address assigned by said first network;
means for establishing a secondary network session between the gateway and a second network;
means for receiving a second real network address for the user, said second real network address assigned by said second network;
means for receiving a packet sent by the user;
means for examining said packet to determine if its destination is said first network or said second network;
means for forwarding said packet to the first network if said packet indicates that its destination is said first network;
means for performing network address translation on said packet if said packet indicates that its destination is said second network; and
means for forwarding said translated packet to said second network if said packet indicates that its destination is said second network.
89. The network gateway of claim 88, further including means for storing said second real network address in a network address translation table in an entry corresponding to said first real network address.
90. The network gateway of claim 88, wherein said primary PPP session and said secondary network session are tunneling sessions.
91. The network gateway of claim 90, wherein said primary PPP session and said secondary network session are L2TP sessions.
92. The network gateway of claim 88, wherein said examining step further includes the steps of:
extracting a destination network address from the packet;
looking up said destination network address in a routing table;
determining that said destination is the first or second network based upon the listing for the destination network address in the routing table; and
determining that said destination is the first or second network based on a default setting if said destination network address is not listed in said routing table.
93. The network gateway of claim 88, wherein said means for performing network address translation include means for extracting a source network address from the packet and means for applying a network address translation mapping scheme to source destination network address.
94. The network gateway of claim 89, wherein said means for performing network address translation include means for extracting a source network address from the packet and means for looking up said source network address in said network address translation table.
95. The network gateway of claim 88, further including:
means for receiving a second packet, said second packet sent from said first network or said second network;
means for examining said second packet to determine if its source is said first network or said second network;
means for performing network address translation on said second packet if said second packet indicates that its source is said second network; and
means for forwarding said second packet to the user.
US09/186,214 1998-11-03 1998-11-03 Multiple network connections from a single PPP link with partial network address translation Expired - Lifetime US6381646B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/186,214 US6381646B2 (en) 1998-11-03 1998-11-03 Multiple network connections from a single PPP link with partial network address translation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09/186,214 US6381646B2 (en) 1998-11-03 1998-11-03 Multiple network connections from a single PPP link with partial network address translation

Publications (2)

Publication Number Publication Date
US20020002621A1 true US20020002621A1 (en) 2002-01-03
US6381646B2 US6381646B2 (en) 2002-04-30

Family

ID=22684094

Family Applications (1)

Application Number Title Priority Date Filing Date
US09/186,214 Expired - Lifetime US6381646B2 (en) 1998-11-03 1998-11-03 Multiple network connections from a single PPP link with partial network address translation

Country Status (1)

Country Link
US (1) US6381646B2 (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020099856A1 (en) * 2001-01-15 2002-07-25 Kazuhiro Shitama Information processing device and method thereof, recording medium and program
US20040001496A1 (en) * 2002-06-21 2004-01-01 Jon Yusko Method and apparatus for PPP auto-connect
WO2004030317A1 (en) * 2002-09-25 2004-04-08 Siemens Aktiengesellschaft Method for transparently exchanging data packets
EP1571800A1 (en) * 2004-03-03 2005-09-07 France Telecom Method and system of a client accessing services provided by a service provider
US20060104280A1 (en) * 2000-03-20 2006-05-18 At&T Corp. Method and apparatus for coordinating a change in service provider between a client and a server with identity based service access management
US7107614B1 (en) * 1999-01-29 2006-09-12 International Business Machines Corporation System and method for network address translation integration with IP security
US20070061883A1 (en) * 1999-07-14 2007-03-15 Symantec Corporation System and method for generating fictitious content for a computer
US20070064649A1 (en) * 2005-09-16 2007-03-22 Tero Makela Two-layer network identification
US20070127456A1 (en) * 2003-10-29 2007-06-07 Siemens Aktiengesellschaft Communications apparatus and method
US20070157315A1 (en) * 1999-08-30 2007-07-05 Symantec Corporation System and method for using timestamps to detect attacks
US7330896B1 (en) * 1999-02-25 2008-02-12 Nortel Networks Limited Correlating data streams of different protocols
US20080141349A1 (en) * 1999-07-14 2008-06-12 Symantec Corporation System and method for computer security
US20080267201A1 (en) * 2001-11-05 2008-10-30 Cisco Technology, Inc. System and method for managing dynamic network sessions
US20090011410A1 (en) * 2004-10-20 2009-01-08 Masato Mitsuhashi Method for tailoring administration of drugs by quantitation of mrna
US20090064331A1 (en) * 1999-07-14 2009-03-05 Symantec Corporation System and method for preventing detection of a selected process running on a computer
US20090207806A1 (en) * 2008-02-20 2009-08-20 Nokia Corporation IP mobility multihoming
US7869436B1 (en) * 2005-10-13 2011-01-11 Cisco Technology, Inc. Methods and apparatus for connecting to virtual networks using non supplicant authentication
US20150271140A1 (en) * 1999-06-15 2015-09-24 Tectia Oyj Tunnelling of Information
CN114128234A (en) * 2020-02-06 2022-03-01 华为云计算技术有限公司 Virtual address allocation for preventing conflicts in a multi-network environment

Families Citing this family (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2290986T3 (en) 1997-03-12 2008-02-16 Nomadix, Inc. NAME TRANSMITTER OR ROUTER.
US7194554B1 (en) 1998-12-08 2007-03-20 Nomadix, Inc. Systems and methods for providing dynamic network authorization authentication and accounting
US8266266B2 (en) 1998-12-08 2012-09-11 Nomadix, Inc. Systems and methods for providing dynamic network authorization, authentication and accounting
US8713641B1 (en) 1998-12-08 2014-04-29 Nomadix, Inc. Systems and methods for authorizing, authenticating and accounting users having transparent computer access to a network using a gateway device
FR2787956B1 (en) * 1998-12-24 2001-02-23 France Telecom METHOD OF ADDRESSING IN A DIGITAL TELECOMMUNICATIONS NETWORK AND NAME AND ADDRESS SERVER IMPLEMENTING SUCH A METHOD
US6563824B1 (en) * 1999-04-20 2003-05-13 3Com Corporation Apparatus and methods for determining the correct workstation within a LAN for a LAN modem to route a packet
US6496867B1 (en) * 1999-08-27 2002-12-17 3Com Corporation System and method to negotiate private network addresses for initiating tunneling associations through private and/or public networks
US6687833B1 (en) * 1999-09-24 2004-02-03 Networks Associates, Inc. System and method for providing a network host decoy using a pseudo network protocol stack implementation
WO2001031885A2 (en) 1999-10-22 2001-05-03 Nomadix, Inc. Gateway device having an xml interface and associated method
US7171492B1 (en) * 2000-02-24 2007-01-30 Utstarcom, Inc. Method and application programming interface for assigning multiple network addresses
US6631416B2 (en) * 2000-04-12 2003-10-07 Openreach Inc. Methods and systems for enabling a tunnel between two computers on a network
US7028334B2 (en) * 2000-04-12 2006-04-11 Corente, Inc. Methods and systems for using names in virtual networks
US7085854B2 (en) * 2000-04-12 2006-08-01 Corente, Inc. Methods and systems for enabling communication between a processor and a network operations center
US7028333B2 (en) * 2000-04-12 2006-04-11 Corente, Inc. Methods and systems for partners in virtual networks
US7047424B2 (en) * 2000-04-12 2006-05-16 Corente, Inc. Methods and systems for hairpins in virtual networks
US7181766B2 (en) * 2000-04-12 2007-02-20 Corente, Inc. Methods and system for providing network services using at least one processor interfacing a base network
US7181542B2 (en) * 2000-04-12 2007-02-20 Corente, Inc. Method and system for managing and configuring virtual private networks
US6996628B2 (en) * 2000-04-12 2006-02-07 Corente, Inc. Methods and systems for managing virtual addresses for virtual networks
US6618757B1 (en) * 2000-05-17 2003-09-09 Nortel Networks Limited System and method for dynamic IP address management
US7146410B1 (en) * 2000-06-07 2006-12-05 Nortel Networks Limited System and method for executing control protocols among nodes in separate IP networks
US6772210B1 (en) * 2000-07-05 2004-08-03 Nortel Networks Limited Method and apparatus for exchanging communications between telephone number based devices in an internet protocol environment
US6876640B1 (en) * 2000-10-30 2005-04-05 Telefonaktiebolaget Lm Ericsson Method and system for mobile station point-to-point protocol context transfer
US20020124095A1 (en) * 2001-03-02 2002-09-05 Sultan Israel Daniel Apparatus and method for sending point-to-point protocol over ethernet
US7293108B2 (en) * 2001-03-15 2007-11-06 Intel Corporation Generic external proxy
US20020138552A1 (en) * 2001-03-21 2002-09-26 Debruine Timothy S. Method and system for optimizing private network file transfers in a public peer-to-peer network
US6978308B2 (en) * 2001-03-21 2005-12-20 International Business Machines Corporation System and method for nesting virtual private networking connections with coincident endpoints
US7533409B2 (en) * 2001-03-22 2009-05-12 Corente, Inc. Methods and systems for firewalling virtual private networks
US20030009561A1 (en) * 2001-06-14 2003-01-09 Sollee Patrick N. Providing telephony services to terminals behind a firewall and /or network address translator
JP3697711B2 (en) * 2001-07-04 2005-09-21 日本電気株式会社 PPP termination device, network device, and LCP echo request response method
JP3625445B2 (en) * 2001-12-13 2005-03-02 株式会社東芝 Network relay device and network relay method
KR100440964B1 (en) * 2001-12-29 2004-07-21 삼성전자주식회사 Method of receiving E-mails in internet fax via only once point-to-point protocol connection
US20030145082A1 (en) * 2002-01-25 2003-07-31 Son Yong Ho NAT device with LAN monitor for remote management
US7395354B2 (en) * 2002-02-21 2008-07-01 Corente, Inc. Methods and systems for resolving addressing conflicts based on tunnel information
US7443865B1 (en) * 2002-04-04 2008-10-28 Cisco Technology, Inc. Multiple network connections from a single PPP link with network address translation
KR100532098B1 (en) * 2002-11-16 2005-11-29 삼성전자주식회사 Incoming and outgoing call system based on duplicate private network
US7660985B2 (en) * 2003-04-30 2010-02-09 At&T Corp. Program security through stack segregation
US7220390B2 (en) * 2003-05-16 2007-05-22 Velocys, Inc. Microchannel with internal fin support for catalyst or sorption medium
US7237267B2 (en) * 2003-10-16 2007-06-26 Cisco Technology, Inc. Policy-based network security management
US7716350B2 (en) * 2003-10-23 2010-05-11 Cisco Technology, Inc. Methods and devices for sharing content on a network
US7607021B2 (en) 2004-03-09 2009-10-20 Cisco Technology, Inc. Isolation approach for network users associated with elevated risk
US20050271047A1 (en) * 2004-06-02 2005-12-08 Huonder Russell J Method and system for managing multiple overlapping address domains
US8312530B2 (en) * 2004-07-12 2012-11-13 Cisco Technology, Inc. System and method for providing security in a network environment using accounting information
US8572721B2 (en) 2006-08-03 2013-10-29 Citrix Systems, Inc. Methods and systems for routing packets in a VPN-client-to-VPN-client connection via an SSL/VPN network appliance
US7769869B2 (en) * 2006-08-21 2010-08-03 Citrix Systems, Inc. Systems and methods of providing server initiated connections on a virtual private network
WO2009151863A2 (en) * 2008-06-10 2009-12-17 Myers Wolin, Llc A network gateway for time-critical and mission-critical networks
US20110085552A1 (en) * 2009-10-14 2011-04-14 Electronics And Telecommunications Research Institute System and method for forming virtual private network
US9455908B2 (en) * 2014-07-07 2016-09-27 Cisco Technology, Inc. Bi-directional flow stickiness in a network environment
US9503363B2 (en) 2015-03-16 2016-11-22 Cisco Technology, Inc. Segment routing label switch paths in network functions virtualization communications networks
US9979629B2 (en) 2015-08-21 2018-05-22 Cisco Technology, Inc. Distribution of segment identifiers in network functions virtualization and software defined network environments

Family Cites Families (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5241594A (en) 1992-06-02 1993-08-31 Hughes Aircraft Company One-time logon means and methods for distributed computing systems
FI91700C (en) 1992-08-14 1994-07-25 Nokia Telecommunications Oy A method for transmitting packet data and a mobile station for a cellular radio system
DE4321458A1 (en) 1993-06-29 1995-01-12 Alcatel Network Services Network management support method and network management facility therefor
JP3425192B2 (en) 1993-08-25 2003-07-07 富士通株式会社 Address information automatic setting processing method and address information setting device
US5555244A (en) 1994-05-19 1996-09-10 Integrated Network Corporation Scalable multimedia network
JPH09510596A (en) * 1994-06-08 1997-10-21 エイチイー・ホールディングス・インコーポレーテッド・ディー ビーエー・ヒューズ・エレクトロニクス Apparatus and method for hybrid network access
US5617417A (en) 1994-09-07 1997-04-01 Stratacom, Inc. Asynchronous transfer mode communication in inverse multiplexing over multiple communication links
US5655077A (en) 1994-12-13 1997-08-05 Microsoft Corporation Method and system for authenticating access to heterogeneous computing services
US5592470A (en) 1994-12-21 1997-01-07 At&T Broadband wireless system and network architecture providing broadband/narrowband service with optimal static and dynamic bandwidth/channel allocation
JPH08235114A (en) 1995-02-28 1996-09-13 Hitachi Ltd Server access method and charge information managing method
US5583862A (en) 1995-03-28 1996-12-10 Bay Networks, Inc. Method and apparatus for routing for virtual networks
JP2770782B2 (en) 1995-05-31 1998-07-02 日本電気株式会社 LAN connection device
US5793763A (en) 1995-11-03 1998-08-11 Cisco Technology, Inc. Security system for network address translation systems
US5740171A (en) 1996-03-28 1998-04-14 Cisco Systems, Inc. Address translation mechanism for a high-performance network switch
US5854901A (en) 1996-07-23 1998-12-29 Cisco Systems, Inc. Method and apparatus for serverless internet protocol address discovery using source address of broadcast or unicast packet
US5684950A (en) 1996-09-23 1997-11-04 Lockheed Martin Corporation Method and system for authenticating users to multiple computer servers via a single sign-on
US5812529A (en) 1996-11-12 1998-09-22 Lanquest Group Method and apparatus for network assessment
US6011910A (en) 1997-04-08 2000-01-04 3Com Corporation Supporting authentication across multiple network access servers
US5944824A (en) 1997-04-30 1999-08-31 Mci Communications Corporation System and method for single sign-on to a plurality of network elements
US6091951A (en) 1997-05-14 2000-07-18 Telxon Corporation Seamless roaming among multiple networks
US6021496A (en) 1997-07-07 2000-02-01 International Business Machines Corporation User authentication from non-native server domains in a computer network
US5991810A (en) 1997-08-01 1999-11-23 Novell, Inc. User name authentication for gateway clients accessing a proxy cache server
US6023724A (en) * 1997-09-26 2000-02-08 3Com Corporation Apparatus and methods for use therein for an ISDN LAN modem that displays fault information to local hosts through interception of host DNS request messages
US6018770A (en) 1997-10-13 2000-01-25 Research In Motion Limited System and method for managing packet-switched connections
US6092196A (en) 1997-11-25 2000-07-18 Nortel Networks Limited HTTP distributed remote user authentication system
US6026441A (en) 1997-12-16 2000-02-15 At&T Corporation Method for establishing communication on the internet with a client having a dynamically assigned IP address
US6009103A (en) 1997-12-23 1999-12-28 Mediaone Group, Inc. Method and system for automatic allocation of resources in a network
US6055236A (en) * 1998-03-05 2000-04-25 3Com Corporation Method and system for locating network services with distributed network address translation
US6112245A (en) * 1998-04-07 2000-08-29 3Com Corporation Session establishment for static links in Point-to-Point Protocol sessions
US6205479B1 (en) 1998-04-14 2001-03-20 Juno Online Services, Inc. Two-tier authentication system where clients first authenticate with independent service providers and then automatically exchange messages with a client controller to gain network access
US6141687A (en) 1998-05-08 2000-10-31 Cisco Technology, Inc. Using an authentication server to obtain dial-out information on a network
US6119160A (en) 1998-10-13 2000-09-12 Cisco Technology, Inc. Multiple-level internet protocol accounting

Cited By (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7107614B1 (en) * 1999-01-29 2006-09-12 International Business Machines Corporation System and method for network address translation integration with IP security
US7330896B1 (en) * 1999-02-25 2008-02-12 Nortel Networks Limited Correlating data streams of different protocols
US20150271140A1 (en) * 1999-06-15 2015-09-24 Tectia Oyj Tunnelling of Information
US20090064331A1 (en) * 1999-07-14 2009-03-05 Symantec Corporation System and method for preventing detection of a selected process running on a computer
US20080141349A1 (en) * 1999-07-14 2008-06-12 Symantec Corporation System and method for computer security
US8549640B2 (en) 1999-07-14 2013-10-01 Symantec Corporation System and method for computer security
US7854005B2 (en) 1999-07-14 2010-12-14 Symantec Corporation System and method for generating fictitious content for a computer
US7827605B2 (en) 1999-07-14 2010-11-02 Symantec Corporation System and method for preventing detection of a selected process running on a computer
US20070061883A1 (en) * 1999-07-14 2007-03-15 Symantec Corporation System and method for generating fictitious content for a computer
US20070157315A1 (en) * 1999-08-30 2007-07-05 Symantec Corporation System and method for using timestamps to detect attacks
US8578490B2 (en) 1999-08-30 2013-11-05 Symantec Corporation System and method for using timestamps to detect attacks
US8724625B2 (en) 2000-03-20 2014-05-13 At&T Intellectual Property Ii, L.P. Method and apparatus for coordinating a change in service provider between a client and a server with identity based service access management
US20100313251A1 (en) * 2000-03-20 2010-12-09 At&T Intellectual Property Ii, L.P. Method and Apparatus for Coordinating a Change in Service Provider Between a Client and a Server with Identity Based Service Access Management
US8396011B2 (en) * 2000-03-20 2013-03-12 At&T Intellectual Property Ii, L.P. Method and apparatus for coordinating a change in service provider between a client and a server with identity based service access management
US7801056B2 (en) * 2000-03-20 2010-09-21 At&T Intellectual Property Ii, L.P. Method and apparatus for coordinating a change in service provider between a client and a server with identity based service access management
US20060104280A1 (en) * 2000-03-20 2006-05-18 At&T Corp. Method and apparatus for coordinating a change in service provider between a client and a server with identity based service access management
US20020099856A1 (en) * 2001-01-15 2002-07-25 Kazuhiro Shitama Information processing device and method thereof, recording medium and program
US20080267201A1 (en) * 2001-11-05 2008-10-30 Cisco Technology, Inc. System and method for managing dynamic network sessions
US8477792B2 (en) * 2001-11-05 2013-07-02 Cisco Technology, Inc. System and method for managing dynamic network sessions
US20040001496A1 (en) * 2002-06-21 2004-01-01 Jon Yusko Method and apparatus for PPP auto-connect
US20060080458A1 (en) * 2002-09-25 2006-04-13 Werner Lindemann Method for transparently exchanging data packets
WO2004030317A1 (en) * 2002-09-25 2004-04-08 Siemens Aktiengesellschaft Method for transparently exchanging data packets
US8626945B2 (en) 2002-09-25 2014-01-07 Siemens Enterprise Communiucations GmbH & Co. KG Method for transparently exchanging data packets
US20070127456A1 (en) * 2003-10-29 2007-06-07 Siemens Aktiengesellschaft Communications apparatus and method
EP1571800A1 (en) * 2004-03-03 2005-09-07 France Telecom Method and system of a client accessing services provided by a service provider
WO2005096587A1 (en) * 2004-03-03 2005-10-13 France Telecom S.A. Method and system enabling a client to access services provided by a service provider
US20090011410A1 (en) * 2004-10-20 2009-01-08 Masato Mitsuhashi Method for tailoring administration of drugs by quantitation of mrna
US20070064649A1 (en) * 2005-09-16 2007-03-22 Tero Makela Two-layer network identification
US7869436B1 (en) * 2005-10-13 2011-01-11 Cisco Technology, Inc. Methods and apparatus for connecting to virtual networks using non supplicant authentication
US20090207806A1 (en) * 2008-02-20 2009-08-20 Nokia Corporation IP mobility multihoming
US8654735B2 (en) 2008-02-20 2014-02-18 Nokia Corporation IP mobility multihoming
CN114128234A (en) * 2020-02-06 2022-03-01 华为云计算技术有限公司 Virtual address allocation for preventing conflicts in a multi-network environment

Also Published As

Publication number Publication date
US6381646B2 (en) 2002-04-30

Similar Documents

Publication Publication Date Title
US6381646B2 (en) Multiple network connections from a single PPP link with partial network address translation
US6490289B1 (en) Multiple network connections from a single PPP link with network address translation
US6801528B2 (en) System and method for dynamic simultaneous connection to multiple service providers
US6996621B1 (en) Method for supporting secondary address delivery on remote access servers
WO2004107671A1 (en) Communication device
JP2003273935A (en) Network-connecting apparatus and method for providing direct connection between network devices in different private networks
EP1168718B1 (en) Method and device to communicate with a device not belonging to the same virtual private network
US7420973B2 (en) Context selection in a network element through subscriber flow switching
US20040083290A1 (en) Software implemented virtual private network service
US7443865B1 (en) Multiple network connections from a single PPP link with network address translation
US6829235B1 (en) Telecommunications network with parallel session function
KR100604566B1 (en) VPN service provisioning method using session agent
Cisco Configuring Protocol Translation and Virtual Asynchronous Devices
Cisco Protocol Translation Session Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Session Commands
Cisco Protocol Translation Session Commands
Cisco Protocol Translation Commands
Cisco Protocol Translation Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Configuration Commands
Cisco Protocol Translation Configuration Commands

Legal Events

Date Code Title Description
AS Assignment

Owner name: CISCO TECHNOLGY, INC., CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ZHANG, SHUJIN;JIN, JANE JIAYING;CHU, JIE;AND OTHERS;REEL/FRAME:009708/0824

Effective date: 19981125

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12