WO2016095439A1

WO2016095439A1 - Equal cost multi-path (ecmp) based packet transmission method and device

Info

Publication number: WO2016095439A1
Application number: PCT/CN2015/080061
Authority: WO
Inventors: 谢密; 张启申; 孟庆明
Original assignee: 中兴通讯股份有限公司
Priority date: 2014-12-18
Filing date: 2015-05-28
Publication date: 2016-06-23
Also published as: CN105791145B; CN105791145A

Abstract

Disclosed are an equal cost multi-path (ECMP) based packet transmission method and device. The method comprises: receiving a packet, and obtaining a hash value of the packet and a base address of a corresponding export encapsulation table; obtaining a quantity of transmission links, and obtaining a modulus value by performing a modulus operation on the hash value and the quantity of transmission links; obtaining encapsulation information from the export encapsulation table according to the base address of the export encapsulation table and the modulus value; and encapsulating the packet according to the encapsulation information, and sending the packet, to at least resolve the problem in the prior art that transmission links cannot evenly share packet transmission.

Description

Message transmission method and device based on equivalent multipath ECMP

Technical field

The present invention relates to the field of communications, and in particular to an ECMP (Equal Cost Multi-Path)-based message transmission method and apparatus.

Background technique

ECMP (Equal Cost Multi-Path) is a technique for improving the shortest path based internal gateway routing protocol in IP networks. In the traditional shortest path algorithm, if two or more shortest paths exist at the same time, the algorithm chooses the optimal one. ECMP has been improved, and traffic is distributed among multiple equal-cost paths. After ECMP is deployed on a MPLS network (Multi-Protocol Label Switching) network, you need to meet the carrier-class protection switching requirements when the link is faulty.

In the related art, FIG. 1 is a flowchart of a method for transmitting ECMP-based messages according to the related art. As shown in FIG. 1, the message transmission device passes MAC address (Media Access Control, media access). The control, the source MAC address, the destination IP address, the source IP address, and other fields are hashed to obtain a hash value. The egress encapsulation table has multiple consecutive entries, corresponding to multiple equal-cost forwarding paths, when the destination destination MAC address, source MAC address, and destination When the fields such as IP and source IP are changed, different hash values are obtained through the hash module. By adding the hash value to the base address of the export encapsulation table, different egress encapsulation table entries can be corresponding to achieve packet sharing. The purpose of forwarding on multiple paths. When N MPLS ECMPs are formed in the MPLS (Multiple Protocol Label Switch) network, all MPLS ECMPs share the shared link. For the number of shared links, the prior art cannot directly take all the hash values, and only a part of the bits can be discarded, and the actual number of links is taken. For example, when the actual number of links is 32, the number of bits is 5. (2 to the 5th power), the possible hash value change is not within 5 bits of the fetch, that is, after hashing different message fields, the lower 5 bits of the hash value are unchanged, which will cause uneven link sharing, resulting in uneven link sharing. The shared flow accuracy exceeded the standard.

Summary of the invention

The present invention provides an ECMP-based message transmission method and apparatus, so as to at least solve the problem that the transmission link cannot uniformly share the message transmission in the related art.

According to an aspect of the present invention, an ECMP-based message transmission method is provided, including: receiving a message, and obtaining a hash value of the packet and a base address of a corresponding egress encapsulation table; acquiring a transmission link Number, and modulo the hash value to the number of the transmission links to obtain a modulus value; according to the base address and location of the egress package table The modulo value obtains the encapsulation information from the egress package table; encapsulates the packet according to the encapsulation information, and sends the packet.

In the embodiment of the present invention, obtaining the encapsulation information from the egress package table according to the base address of the egress package table and the modulus value includes: obtaining a base address of the share policy table, where the share policy table includes Determining an offset address of the transport link in the egress package table; obtaining an offset address of the egress package table from the share policy table according to a base address of the share policy table and the modulus value; The base address of the egress package table and the offset address obtain encapsulation information from the egress package table.

In the embodiment of the present invention, the obtaining the number of transmission links includes: acquiring the number of the transmission links from the stored transmission link number table.

In the embodiment of the present invention, when the transmission link is faulty, the transmission link number table is updated, and the offset address corresponding to the transmission link in the sharing policy table is deleted.

In the embodiment of the present invention, obtaining the offset address of the egress encapsulation table from the base of the share policy table and the modulus value from the share policy table includes: base address according to the share policy table and The modulo value is obtained as an index of the sharing policy table; the loyalty policy table index is used to query the sharing policy table corresponding to the index of the sharing policy table, and the offset address of the egress encapsulation table is obtained, where the sharing policy is The table stores the mapping relationship between the index of the sharing policy table and the offset address of the egress encapsulation table; obtaining the encapsulation information from the egress encapsulation table according to the base address of the egress encapsulation table and the offset address includes: Deriving the egress package table index according to the base address of the egress package table and the offset address; querying an egress package table corresponding to the egress package table index according to the egress package table index, and obtaining the encapsulation information, The egress package table stores a correspondence between the egress package table index and the encapsulation information.

According to another aspect of the present invention, an ECMP-based message transmission apparatus is provided, including: an obtaining module, configured to receive a message, and obtain a hash value of the packet and a corresponding base address of an export encapsulation table. And obtaining a number of transmission links; the processing module is configured to modulo the number of transmission links acquired by the obtaining module by using a hash value obtained by the acquiring module to obtain a modulus value; and the acquiring module is further configured to: And obtaining the encapsulation information from the egress package table according to the base address of the egress package table obtained by the obtaining module and the modulus value obtained by the processing module; and the encapsulating and sending module is configured to encapsulate the encapsulation information acquired according to the acquiring module. Describe the message and send the message.

In the embodiment of the present invention, the acquiring module is configured to obtain a base address of the sharing policy table, where the sharing policy table includes an offset address of the transmission link in the egress encapsulation table, and according to the The base address of the share policy table and the modulus value are obtained from the share policy table, and the offset address of the egress package table is obtained, and the egress package is encapsulated according to the base address of the egress package table and the offset address. The package information is obtained in the table.

In the embodiment of the present invention, the acquiring module is configured to acquire the number of the transmission links from the stored transmission link number table.

In the embodiment of the present invention, the processing module is further configured to: when the transmission link is faulty, update the transmission link number table, and the corresponding to the transmission link in the sharing policy table The offset address is deleted.

In the embodiment of the present invention, the acquiring module is configured to obtain the sharing policy table index according to the base address of the sharing policy table and the modulus, and query the sharing policy table according to the sharing policy table index. Indexing a corresponding sharing policy table, and obtaining an offset address of the egress encapsulation table, where the sharing policy table stores a correspondence between the sharing policy table index and an offset address of the egress encapsulation table; The obtaining module is configured to obtain the egress encapsulation table index according to the base address of the egress encapsulation table and the offset address, and query an egress encapsulation table corresponding to the egress encapsulation table index according to the egress encapsulation table index, and Obtaining the encapsulation information, wherein the egress package table stores a correspondence between the egress package table index and the encapsulation information.

In the embodiment of the present invention, the packet transmission apparatus is used to receive the packet, and obtain the hash value of the packet and the corresponding base address of the egress encapsulation table, obtain the number of transmission links, and transmit the hash value to the packet. The number of links is obtained by modulo, and the encapsulation information is obtained from the egress package table according to the base address of the egress package table and the modulus value, and the packet is encapsulated according to the encapsulation information, and the packet is sent to solve the problem. In the prior art, the transmission link cannot uniformly share the message transmission, thereby improving the load sharing accuracy.

DRAWINGS

The drawings described herein are intended to provide a further understanding of the invention, and are intended to be a part of the invention. In the drawing:

1 is a flowchart of a method for ECMP-based message transmission according to the related art;

2 is a flowchart of a method for ECMP-based message transmission according to an embodiment of the present invention;

FIG. 3a is a schematic diagram of a sharing policy table according to an embodiment of the present invention; FIG.

FIG. 3b is a schematic diagram of a transmission link number table according to an embodiment of the present invention; FIG.

4 is a flowchart of another ECMP-based message transmission method according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of message transmission by a message transmission apparatus according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic diagram of another message transmission apparatus performing message transmission according to an embodiment of the present invention; FIG.

FIG. 7 is a schematic structural diagram of a message transmission apparatus according to an embodiment of the present invention.

detailed description

The invention will be described in detail below with reference to the drawings in conjunction with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict.

In this embodiment, a method for ECMP-based message transmission is provided. FIG. 2 is a flowchart of ECMP-based message transmission according to an embodiment of the present invention. As shown in FIG. 2, the process includes the following steps. :

Step S202, receiving a packet, and obtaining a hash value of the packet and a base address of the corresponding export encapsulation table;

Step S204, obtaining the number of transmission links, and modulating the number of the transmission links to obtain a modulus value;

Step S206, obtaining encapsulation information from the egress package table according to the base address of the egress package table and the modulus value;

Step S208, the packet is encapsulated according to the encapsulation information, and the packet is sent.

Through the above steps, the problem that the transmission link cannot uniformly share the message transmission in the prior art is solved, thereby improving the sharing precision and improving the load sharing precision.

In the embodiment of the present invention, the base address of the distribution policy table is obtained, and the offset address of the egress package table is obtained from the share policy table according to the base address of the share policy table and the modulus value, according to the basis of the egress package table. The address and the offset address obtain the encapsulation information from the egress encapsulation table, so that multiple ECMP groups can be configured to correspond to one sharing policy table.

FIG. 3a is a schematic diagram of a sharing policy table according to an embodiment of the present invention. As shown in FIG. 3a, the sharing policy table includes an offset address of the transmission link in the egress encapsulation table.

It should be noted that the sharing policy table includes consecutive M entries (M is the number of transmission links), and the table is based on the link interface combination and the link-sharing weight aggregation, that is, the ECMP service with the same link interface and the same weight. Share a shared strategy table.

In the embodiment of the present invention, the number of the transmission links is obtained from the stored transmission link number table.

FIG. 3b is a schematic diagram of a transmission link number table according to an embodiment of the present invention. As shown in FIG. 3b, the transmission link number table stores the number of transmission links, and the table is based on a link interface combination and a link. The ECMP service with the same link interface and the same weight is shared.

In the embodiment of the present invention, when the transmission link is faulty, the transmission link number table is updated, and the offset address corresponding to the transmission link in the sharing policy table is deleted, so that although there are multiple ECMP groups However, switching a shared strategy table can achieve one-to-one switching, avoiding switching of each egress package table, and significantly improving handover performance.

In the embodiment of the present invention, the sharing policy table index is obtained according to the base address of the sharing policy table and the modulus value, and the sharing policy table corresponding to the sharing policy table index is queried according to the sharing policy table index, and the export encapsulation table is obtained. The offset information, the encapsulation information obtained from the egress encapsulation table according to the base address of the egress encapsulation table and the offset address includes: wherein the sharing policy table stores the offset of the sharing policy table index and the egress encapsulation table The correspondence of addresses.

In the embodiment of the present invention, the egress package table corresponding to the egress package table index is queried according to the egress package table index, and the package information is obtained, wherein the egress package table stores the egress package table index and the corresponding information of the package information. relationship.

The embodiment of the present invention provides a method for transmitting a message based on ECMP, and FIG. 4 is a flowchart of another method for transmitting ECMP based message according to an embodiment of the present invention. As shown in FIG. The executor may be a message transmission device, and the message transmission device may be a router. The embodiment of the present invention is not limited thereto. The process of the method includes:

S401. The message transmission device receives the packet, and obtains a hash value of the packet and a base address of the corresponding export encapsulation table.

The packet processing device obtains the destination MAC address, source MAC address, destination IP address, and source IP address of the packet to obtain a hash value.

S402. The message transmission device obtains the number of transmission links from the stored transmission link number table, and modulates the number of the transmission links to obtain a modulus value.

For example, in the embodiment of the present invention, all 16-bit (bit) hash values are used to perform a modulo operation on the number of shared links (ie, the remainder), and the value after the modulo operation does not exceed 8 due to the characteristics of the modulo operation, thereby avoiding The part of the hash value taken is unchanged or unevenly changed.

S403. The message transmission device obtains the share policy table index according to the base address of the share policy table and the modulus value.

S404: The message transmission device queries the sharing policy table corresponding to the index of the sharing policy table according to the sharing policy table index, and obtains an offset address of the egress encapsulation table.

The sharing policy table stores a correspondence between the sharing policy table index and an offset address of the egress encapsulation table.

S405. The message transmission device obtains the egress package table index according to the base address of the egress package table and the offset address.

S406. The message transmission device queries the egress package table corresponding to the egress package table index according to the egress package table index, and obtains the package information.

The egress package table stores a correspondence between the egress package table index and the encapsulation information.

S407. The packet transmission device encapsulates the packet according to the encapsulation information, and sends the packet.

It should be noted that, because different ECMP group export encapsulation information is different (that is, MPLS labels are different), different egress package tables correspond to different ECMP groups.

For example, 1000 routes are learned from each of the eight shared links. This route forms load sharing. There are eight egresses. The egress MPLS label (encapsulated into outgoing packets) corresponding to each egress is different. That is, each route corresponds to 8 outgoing MPLS labels, and 1000 routes correspond to 1000 egress encapsulation tables. Each egress encapsulation table contains 8 entries, and each entry stores an outgoing MPLS label.

In summary, FIG. 5 is a schematic diagram of message transmission by a message transmission apparatus according to an embodiment of the present invention. As shown in FIG. 5, FIG. 5 is a schematic diagram of message transmission by the message transmission apparatus according to an embodiment of the present invention. The packet processing device obtains the destination MAC, source MAC, destination IP, source IP, and other fields to obtain a hash value by hashing, and reads the number of transmission links to obtain the number of transmission links; the obtained hash value pair The number of transmission links is modulo, and the modulus value is obtained. Due to the characteristics of the modulo operation, the modulus value does not exceed the number of transmission links, and the obtained modulus value is added according to the base address of the sharing strategy table (the modulus value is the shared strategy table offset). The index of the share policy table is obtained, and the corresponding share policy table entry is found, and the export package table offset is obtained. The export package table index is obtained according to the obtained offset value of the export package table base address, and the corresponding export package table table is found. Item, obtains the export package information, and distributes the message according to the package information and sends the message.

For example, FIG. 6 is a schematic diagram of another message transmission apparatus performing message transmission according to an embodiment of the present invention. As shown in FIG. 6, N ECMP groups share one 8 links (link 1 to link 8 respectively). Interface link group, and share a shared policy table. At this time, the value recorded in the number of transmission link tables is 8, and the sharing policy table The offset addresses of the eight links are sequentially recorded. When the third link fails, the packet transmission device deletes the offset address corresponding to the third link of the sharing policy table, and the transmission link bibliography is The value recorded in the record is adjusted from 8 to 7, so that only one sharing strategy table needs to be switched, thereby improving the switching performance.

The foregoing implementation manner solves the problem that the transmission link cannot uniformly share the packet transmission in the prior art, thereby improving the accuracy of the sharing and improving the load sharing precision. In addition, when the transmission link is faulty, only one sharing strategy is switched. The table can be used to achieve one-to-one switching, avoiding the switching of each egress package table, and significantly improving the switching performance.

In this embodiment, a message transmission device is also provided, which is used to implement the foregoing embodiments and preferred embodiments, and has not been described again. As used below, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated.

FIG. 7 is a structural block diagram of a message transmission apparatus according to an embodiment of the present invention. As shown in FIG. 7, the apparatus 70 includes:

The obtaining module 71 is configured to receive the packet, obtain the hash value of the packet and the base address of the corresponding egress encapsulation table, and obtain the number of transmission links. The processing module 72 is configured to obtain the acquisition module 71. The hash value is obtained by modulating the number of transmission links obtained by the obtaining module to obtain a modulus value; the obtaining module 71 is further configured to: according to the base address of the egress encapsulation table acquired by the obtaining module 71 and the modulus value obtained by the processing module The encapsulation information is obtained in the egress package table. The encapsulation sending module 73 is configured to encapsulate the packet according to the encapsulation information acquired by the acquisition module 71, and send the packet.

In the embodiment of the present invention, the obtaining module 71 is further configured to obtain a base address of the sharing policy table, where the sharing policy table includes an offset address of the transmission link in the egress encapsulation table, and according to the sharing policy table The base address and the modulus value obtain an offset address of the egress package table from the share policy table, and obtain encapsulation information from the egress package table according to the base address of the egress package table and the offset address.

In the embodiment of the present invention, the obtaining module 71 is further configured to obtain the number of the transmission links from the stored transmission link number table.

In the embodiment of the present invention, the processing module 72 is further configured to: when the transmission link is faulty, update the transmission link number table, and delete the offset address corresponding to the transmission link in the sharing policy table.

In the embodiment of the present invention, the obtaining module 71 is further configured to obtain the index of the sharing policy table according to the base address of the sharing policy table and the modulus, and query the sharing corresponding to the index of the sharing policy table according to the index of the sharing policy table. a policy table, and obtaining an offset address of the egress encapsulation table, where the sharing policy table stores a correspondence between the index of the sharing policy table and an offset address of the egress encapsulation table;

The obtaining module 71 is further configured to obtain the egress encapsulation table index according to the base address of the egress encapsulation table and the offset address, and query an egress encapsulation table corresponding to the egress encapsulation table index according to the egress encapsulation table index, and obtain the Encapsulation information, wherein the egress package table stores a correspondence between the egress package table index and the encapsulation information.

The above device solves the problem that the transmission link cannot uniformly share the message transmission in the prior art, thereby improving the sharing precision and improving the load sharing precision.

In summary, the purpose of the embodiment of the present invention is to perform a modulo operation by taking more bits of a hash value obtained from a hash module to improve load sharing accuracy, even if each link is evenly shared; The common part of the egress encapsulation table in the prior art, that is, the common link, is separated and placed in the sharing policy table, so that multiple ECMP groups have the same sharing policy table because of the shared link, when the link occurs. In the case of a fault, although there are multiple ECMP groups, switching a shared policy table can achieve multiple-to-one switching, which can significantly improve the switching performance.

Obviously, those skilled in the art should understand that the above modules or steps of the embodiments of the present invention can be implemented by a general computing device, which can be concentrated on a single computing device or distributed in multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device such that they may be stored in the storage device by the computing device and, in some cases, may be different from The steps shown or described are performed sequentially, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps thereof are fabricated into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

As described above, the above embodiments and the preferred embodiments solve the problem that the transmission link cannot uniformly share the message transmission in the prior art, thereby improving the load sharing accuracy.

Claims

A message transmission method based on equivalent multipath ECMP, comprising:

Receiving a packet, and obtaining a hash value of the packet and a base address of the corresponding export encapsulation table;

Obtaining a number of transmission links, and modulating the hash value to a number of the transmission links to obtain a modulus value;

Obtaining package information from the egress package table according to a base address of the egress package table and the modulus value;

And encapsulating the packet according to the encapsulation information, and sending the packet.
The method of claim 1, wherein obtaining the package information from the egress package table according to the base address of the egress package table and the modulus value comprises:

Obtaining a base address of the sharing policy table, where the sharing policy table includes an offset address of the transmission link in the egress encapsulation table;

Obtaining an offset address of the egress package table from the share policy table according to the base address of the share policy table and the modulus value;

Encapsulating information is obtained from the egress package table according to the base address of the egress package table and the offset address.
The method of claim 2 wherein said obtaining the number of transmission links comprises:

The number of the transmission links is obtained from the stored number of transmission link tables.
The method according to claim 3, wherein, when the transmission link fails, the transmission link number table is updated, and the offset address corresponding to the transmission link in the sharing policy table is deleted. .
The method according to any one of claims 2 to 4, wherein the offset address of the egress package table obtained from the share policy table according to the base address of the share policy table and the modulus value comprises:

Obtaining the share policy table index according to the base address of the share policy table and the modulus value;

Querying, according to the share policy table index, the share policy table corresponding to the share policy table index, and obtaining an offset address of the export package table, where the share policy table stores the share policy table index and the Correspondence between offset addresses of the export encapsulation table;

Obtaining the package information from the egress package table according to the base address of the egress package table and the offset address includes:

Obtaining the egress package table index according to the base address of the egress package table and the offset address;

Querying, according to the egress encapsulation table index, an egress encapsulation table corresponding to the egress encapsulation table index, and obtaining the encapsulation information, where the egress encapsulation table stores a correspondence between the egress encapsulation table index and the encapsulation information .
A message transmission device based on equivalent multipath ECMP, comprising:

Obtaining a module, configured to receive a packet, obtain a hash value of the packet, a base address of the corresponding export encapsulation table, and obtain a number of transmission links;

a processing module, configured to modulo the number of transmission links acquired by the acquiring module by using a hash value obtained by the acquiring module to obtain a modulus value;

The obtaining module is further configured to obtain, according to the base address of the egress package table acquired by the obtaining module and the modulus value obtained by the processing module, the encapsulation information from the egress package table;

The encapsulating and sending module is configured to encapsulate the packet according to the encapsulation information acquired by the acquiring module, and send the packet.
The apparatus according to claim 6, wherein the obtaining module is further configured to acquire a base address of the sharing policy table, wherein the sharing policy table includes an offset address of the transmission link in the egress encapsulation table And obtaining an offset address of the egress package table from the share policy table according to the base address of the share policy table and the modulus value, and according to the base address and the offset address of the egress package table Encapsulation information is obtained from the egress package table.
The apparatus of claim 7, wherein the acquisition module is further configured to obtain the number of the transmission links from a stored list of transmission link numbers.
The apparatus according to claim 8, wherein said processing module is further configured to: when said transmission link fails, update said transmission link number table, and said transmission link in said sharing policy table The corresponding offset address is deleted.
The apparatus according to any one of claims 7 to 9, wherein

The obtaining module is further configured to: obtain the index of the sharing policy table according to the base address of the sharing policy table and the modulus value, and query the index corresponding to the sharing policy table index according to the sharing policy table index Sharing a policy table, and obtaining an offset address of the egress encapsulation table, where the sharing policy table stores a correspondence between the sharing policy table index and an offset address of the egress encapsulation table;

The obtaining module is further configured to obtain the egress encapsulation table index according to the base address of the egress encapsulation table and the offset address, and query the egress encapsulation corresponding to the egress encapsulation table index according to the egress encapsulation table index And obtaining the encapsulation information, wherein the egress package table stores a correspondence between the egress package table index and the encapsulation information.