CN1889505A

CN1889505A - Method and system for aiding CPU to retransmit message

Info

Publication number: CN1889505A
Application number: CNA2006100990524A
Authority: CN
Inventors: 章国栋; 董书友
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-07-17
Filing date: 2006-07-17
Publication date: 2007-01-03
Anticipated expiration: 2026-07-17
Also published as: CN100446501C

Abstract

A method for assisting CPU to retransmit message includes configuring access control listing on network processor to let said processor obtain channel package protocol type and message service type, packaging message head then sending package message to CPU, carrying out retransmission of message by CPU according to received channel package protocol type and received message service type. The system used to realize said method is also disclosed.

Description

A kind of method and system of aiding CPU to retransmit message

Technical field

The present invention relates to network communication field, particularly a kind of method and system of aiding CPU to retransmit message.

Background technology

The forwarding plane of routing forwarding equipment is finished by NP (Network Processor, network processing unit) and two forwarding engines cooperations of CPU in the prior art.NP is responsible for the up routing table look-up forwarding work of message, behind the intact message of downlink processing, hands to CPU; CPU operation TM (Traffic Management, traffic management) function, wherein, important work is QoS (Quality of Service, the service quality) function of finishing the descending message that forwards from NP, cooperates the message forwarding work of NP.

From link layer protocol, CPU has two classes: FR (Frame Relay from the message that NP receives, frame relay) type and non-FR type, wherein, non-FR type comprises: PPP (Point-to-Point Protocol, peer-peer protocol), HDLC (High Data LinkControl, High-Level Data Link Control) etc.

Message to the FR type, the NP message is IP or MPLS (Multi-Protocol Label Switch, when multiprotocol label switching) transmitting, NP send CPU TM to handle after finishing the FR encapsulation, the frame that TM calls FR sends function, does PVC (Permanent Virtual Circuit, the PVC) scheduling under the interface earlier, do the interface scheduling then, forward at last.

To non-FR type, there is not the processing of FRQoS (Frame Relay Quality of Service, frame relay service quality), the QoS that directly calls general-purpose interface sends function and does the interface scheduling, forwards.

Routing forwarding equipment has used NP and CPU simultaneously, and message forwarding needs both cooperation to finish, and the specific implementation process is as follows:

NP hands to CPU to message after handling uplink and downlink routing table look-up forwarding work;

After CPU receives message from NP, from the privately owned heading of NP encapsulation, take out channel number channel_id, inquire about the interface data structure if_net that is kept at the CPU side, obtain the tunneling of respective channel with channel_id.

Configuration by ACL (Access Control List, Access Control List (ACL)) is carried out traffic classification to message, obtains the type of service of message.

Tunneling according to passage is judged:

If tunneling is PPP/HDLC, message is directly done the interface scheduling, forwards.

If tunneling is FR, under the situation that has enabled FRTS, message is done the PVC scheduling under the interface earlier, does the interface scheduling then, forwards at last; Under the situation that does not enable FRTS, message is directly done the interface scheduling, forwards.

Be scheduling at interface under the situation of CBWFQ (Class-based Weighted Fair Queuing is based on the Weighted Fair Queuing of classification),, message gone into the corresponding formation of CBWFQ according to the type of service of message.

The shortcoming of prior art:

NP is when giving CPU downlink message, can not carry passage tunneling information and type of service and give CPU, CPU is for each message of receiving, all need analytic message, and be correspondingly processed, obtain the type of service (EF/AF4/AF3/AF2/AF1/BE) of the tunneling (PPP/HDLC/FR) and the message of exit passageway.

Although the disposal ability of NP is enough, because CPU need make above-mentioned process of analysis to each message, cause the burden of CPU, the bottleneck of whole forwarding performance has influence on the forwarding performance of whole routing forwarding equipment at CPU.

Summary of the invention

CPU E-Packets burden heavily in the prior art in order to solve, and influences the forwarding performance of whole routing forwarding equipment, the invention provides a kind of method and system of aiding CPU to retransmit message.

Technical scheme of the present invention is as follows:

The invention provides a kind of method of aiding CPU to retransmit message, Access Control List (ACL) be configured on the network processing unit, and carry out following steps:

Steps A: after network processing unit is received message, obtain exit passageway tunneling type, carry out the type of service that traffic classification obtains message according to the configuration of Access Control List (ACL) by the channel table of searching the exit passageway correspondence;

Step B: network processing unit is placed on heading to the type of service of passage tunneling type and message, and heading is encapsulated, and the message after will encapsulating then sends to CPU:

Step C: after described CPU receives message, obtain passage tunneling type and message traffic type according to heading;

Step D: described CPU E-Packets according to tunneling type and message traffic type.

Described step B specifically comprises:

Network processing unit is placed on heading to the binary coding of the type of service of the binary coding of passage tunneling type and message, and heading is encapsulated, and then the message after the encapsulation is sent to CPU.

It is described that what heading was encapsulated employing is ether SNAP encapsulation format.

The step that described binary coding the type of service of the binary coding of passage tunneling type and message is placed on heading is specially:

The binary coding of described passage tunneling type is placed on the high byte of the type field of heading, the binary coding of the type of service of described message is placed on the low byte of the type field of described heading.

Described step C specifically comprises:

Step C1: after described CPU receives described message, obtain the binary coding of high low byte from the type field of heading;

Step C2: described CPU decodes to described binary coding and obtains passage tunneling type and message traffic type.

The present invention also provides a kind of system of aiding CPU to retransmit message, described system comprises network processing unit and CPU, described network processing unit comprises generation Access Control List (ACL) module, network processing unit type acquisition module and encapsulation and forwarding module, and described CPU comprises the cpu type acquisition module and the module that E-Packets;

Described generation Access Control List (ACL) module is used to generate Access Control List (ACL);

Described network processing unit type acquisition module is used for network processing unit receive message after, obtain exit passageway tunneling type by the channel table of searching the exit passageway correspondence, carry out the type of service that traffic classification obtains message according to the configuration of Access Control List (ACL);

Described encapsulation and forwarding module are used for that described network processing unit is obtained the passage tunneling type of type block acquisition and the type of service of message is placed on heading, and heading is encapsulated, and the message after will encapsulating then sends to CPU and obtains type block;

Described cpu type acquisition module obtains passage tunneling type and message traffic type according to heading after being used to receive the message of described encapsulation and forwarding module transmission;

The described module that E-Packets is used for described CPU and E-Packets according to tunneling type and message traffic type.

Described encapsulation and forwarding module specifically comprise encapsulation unit and retransmission unit;

Described encapsulation unit is used for network processing unit the binary coding of the type of service of the binary coding of passage tunneling type and message is placed on heading, and heading is encapsulated;

Described retransmission unit is used for that the message after the encapsulation unit encapsulation is sent to described CPU and obtains type block.

Described cpu type acquisition module specifically comprises binary coding acquiring unit and decoding unit;

After described binary coding acquiring unit is used to receive the message of described retransmission unit module transmission, obtain the binary coding of high low byte from the type field of heading;

Described decoding unit is used for CPU and obtains binary coding that the binary coding unit obtains and decode and obtain passage tunneling type and message traffic type described.

The beneficial effect that technical solution of the present invention is brought:

Use NP and cooperate CPU to E-Packet, CPU is simplified the handling process of message, improved the forwarding performance of routing device;

Be optimized by the forwarding performance to CPU, making E-Packets has accomplished the E3 linear speed.

Description of drawings

Fig. 1 is the method flow diagram of aiding CPU to retransmit message provided by the invention;

Fig. 2 is the system schematic of aiding CPU to retransmit message provided by the invention.

Embodiment

The invention will be further described below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention.

The present invention is configured in ACL on the NP, make complicated traffic classification or make BA (Behavior Aggregate by NP, the behavior gathering) simple traffic classification obtains the type of service of message, and search exit passageway tunneling information by NP, CPU does not just need analytic message like this, has simplified the flow process that CPU E-Packets.

The interface of NP and CPU is GMII (Gigabit Media Independent Interface, a gigabit Media Independent Interface), adopts ether SNAP encapsulation.

Referring to Fig. 1, the concrete steps of the method for a kind of aiding CPU to retransmit message of the present invention are as follows:

Step 101:NP receives the message that forwarded upstream is come, search corresponding channel table (channel table of the prior art also is to be placed on the NP) according to the exit passageway in the heading, obtain the type of exit passageway tunneling, the type of described passage tunneling has the PPP of finger type, the HDLC type, FR type etc.

Step 102:NP disposes according to ACL and makes complicated traffic classification or make the type of service that the BA simple traffic classification obtains message, the type of service of described message comprises: EF (Expedited Forwarding, transmit fast), AF4 (Assured Forwarding guarantees to transmit), AF3, AF2, AF1, BE (Best Effort transmits as possible).

Step 103:NP is placed on the high byte of the TYPE (type field) of heading to the binary coding of passage tunneling type, and the binary coding of the type of service of message is placed on the low byte of the TYPE (type field) in the heading.

Wherein, the binary coding of passage tunneling type refers to the PPP type is represented with binary number 000 that the HDLC type is represented with binary number 001, and the FR type is represented with binary number 010, the corresponding relation that is passage tunneling type and binary number is: PPP-000

HDLC-001，

FR-010；

The binary coding of type of service is:

BE-000，AF1-001，AF2-010，AF3-011，AF4-100，EF-101。

Step 104:NP encapsulates heading, and the message after the encapsulation is sent to CPU.Encapsulation can be adopted ether SNAP encapsulation or POS encapsulation, and present embodiment adopts the privately owned heading Ptag of ether SNAP encapsulation, and its encapsulation format is as shown in table 1:

Purpose MAC	Purpose MAC
Purpose MAC	Purpose MAC	Source MAC	Source MAC
LENGTH	Message length	Source MAC	Source MAC
LENGTH	Message length	DSAP	0Xaa
SSAP	0Xaa	DSAP	0Xaa
SSAP	0Xaa	CTRL	0x03
OUI	0x000000	CTRL	0x03
OUI	0x000000	TYPE	TYPE territory (2Bytes)
Channel_id	Channel number	TYPE	TYPE territory (2Bytes)
Channel_id	Channel number	CI	The CI value
PAYLOAD	Message	CI	The CI value

Table 1

TYPE territory among the heading Ptag is 2 bytes, and wherein high byte is used for carrying the passage tunneling of message, and low byte is used for carrying the type of service of message.

After step 105:CPU received the message of sending from NP, directly the type field from privately owned heading obtained high low byte binary coding.

Step 106:CPU obtains passage tunneling type and message traffic type according to the binary coding definition decoding of described passage tunneling type and message traffic type.

Step 107:CPU judges whether the passage encapsulated type is the FR type, if carry out step 109; Otherwise carry out step 110.

Step 108: whether the FRTS that judges interface enables, if, carry out step 111, promptly carry out the interface scheduling and E-Packet; Otherwise carry out step 110.

Step 109: directly do the interface scheduling, the CBWFQ formation is adopted in the interface scheduling, goes into corresponding C BWFQ formation respectively according to the message traffic type and E-Packets.

Step 110: do 2 layers of scheduling, do the PVC scheduling earlier, remake the interface scheduling, the interface scheduling adopts FIFO (First-In-First-Out, first in first out) formation to E-Packet.

Referring to Fig. 2, the present invention also provides a kind of system of aiding CPU to retransmit message, described system comprises network processing unit and CPU, described network processing unit comprises generation Access Control List (ACL) module, network processing unit type acquisition module and encapsulation and forwarding module, and described CPU comprises the cpu type acquisition module and the module that E-Packets;

Above-described embodiment, the present invention embodiment a kind of more preferably just, the common variation that those skilled in the art carries out in the technical solution of the present invention scope and replacing all should be included in protection scope of the present invention.

Claims

1. the method for an aiding CPU to retransmit message is characterized in that, Access Control List (ACL) is configured on the network processing unit, and carries out following steps:

Step B: network processing unit is placed on heading to the type of service of passage tunneling type and message, and heading is encapsulated, and the message after will encapsulating then sends to CPU;

2. the method for aiding CPU to retransmit message as claimed in claim 1 is characterized in that, described step B specifically comprises:

3. the method for aiding CPU to retransmit message as claimed in claim 2 is characterized in that, described what heading was encapsulated employing is ether SNAP encapsulation format.

4. the method for aiding CPU to retransmit message as claimed in claim 3 is characterized in that, the step that described binary coding the type of service of the binary coding of passage tunneling type and message is placed on heading is specially:

5. the method for aiding CPU to retransmit message as claimed in claim 4 is characterized in that, described step C specifically comprises:

6. the system of an aiding CPU to retransmit message, described system comprises network processing unit and CPU, it is characterized in that, described network processing unit comprises generation Access Control List (ACL) module, network processing unit type acquisition module and encapsulation and forwarding module, and described CPU comprises the cpu type acquisition module and the module that E-Packets;

7. the system of aiding CPU to retransmit message as claimed in claim 6 is characterized in that, described encapsulation and forwarding module specifically comprise encapsulation unit and retransmission unit;

8. the system of aiding CPU to retransmit message as claimed in claim 7 is characterized in that, described cpu type acquisition module specifically comprises binary coding acquiring unit and decoding unit;