CN100349424C

CN100349424C - Detecting method for Link routine state

Info

Publication number: CN100349424C
Application number: CNB031499104A
Authority: CN
Inventors: 陈武茂; 左文树; 刘毓
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2003-07-29
Filing date: 2003-07-29
Publication date: 2007-11-14
Anticipated expiration: 2023-07-29
Also published as: CN1578234A

Abstract

The present invention discloses a method for detecting a link state, which comprises: A) setting one accelerating module, receiving a link detecting message from a user by the accelerating module; B) recording the receiving state of the link detecting message of the user, judging whether the link detecting message is a user request responding message or not, if true, returning the user request responding message to the user, executing step C, else, directly executing step C; C) determining the link state by a control module according to the receiving state of the link detecting message of the user. The present invention can effectively reduce the load of a CPU when an access server carries out link detection, so that the performance of a system is improved, and the robustness of the system is enhanced.

Description

A kind of detection method of Link State

Technical field

The present invention relates to access technology, specifically, relate to the detection method of Link State between peer-entities.

Background technology

In the access service of Internet, access server and each insert the Link State of safeguarding each bar link between the user according to access protocol.Access protocol can be point-to-point (PPP) agreement or various bearing protocol, for example, is carried on asynchronous transmission mode point to point (PPP over ATM) agreement, is carried on Ethernet point-to-point (PPP over Ethernet) agreement.

When the user is linked into network by access server, between user and access server, set up link.After link establishment well, detect the state of link as follows according to access protocol: server and user send out the request back message using at a certain time interval mutually, and after receiving the other side's request back message using, response message is responded in one of loopback.If a side of link does not receive the other side's request back message using for a long time, perhaps wrong when the response response message of the other side's response, perhaps not response thinks that then fault has taken place link.Either party of link can cause the dismounting of link when thinking link occurs fault.

The realization principle of the method for the state of above-mentioned detection link as shown in Figure 1.Access server comprises control module and data forwarding processing module, control module is realized by software usually, in order to finish to the control of equipment and the processing of control message, be responsible for the forwarding and the maintenance of information such as various user profile, converting route, Link State, therefore request back message using and the response response message that is above-mentioned detection Link State from all the control messages in the user's message, link detection message all given the control module processing.The data forwarding processing module is realized by hardware usually, utilizes above-mentioned information to finish the forwarding of user data message.

Along with the increase of demand, the number of users that access server inserted is more and more, and concurrent number of users may be up to thousands of.The control module of access server need detect thousands of links simultaneously, receives and dispatches a large amount of messages, has greatly increased the load of CPU.In case CPU can not in time send the request back message using because load is excessive, in the time of can not in time responding user's request back message using, will cause a large number of users link to be removed, thereby cause user's interruption of surfing the Net.

Summary of the invention

The object of the present invention is to provide a kind of detection method of Link State, to reduce the load of access server CPU when the maintenance link.

The present invention is achieved through the following technical solutions:

A kind of detection method of Link State is provided with an accelerating module that is independent of control module hardware of living in, and this method may further comprise the steps:

A) the accelerating module reception is asked back message using and user response response message from user's user;

B) whether for a long time the expression of writing down this user's correspondence does not receive the accepting state that the user asks back message using or user response response message, if what receive is that the user asks back message using, then return the response response message to this user, execution in step C, if what receive is the user response response message, then direct execution in step C;

C) control module reads the accepting state of described record, determines the state of respective links according to the accepting state that reads.

Described step C further comprises, described accepting state by each user's correspondence of accelerating module periodic refreshing, control module judges whether that the user who does not receive from the user for a long time asks back message using or user response response message, if, judge that link work is undesired, otherwise, judge that link is normal.

Preferably, steps A further comprises, receive after the user asks back message using or user response response message, ask to extract user profile back message using or the user response response message from the user, whether the link of checking the user according to user profile is in open mode, if execution in step B then, otherwise abandon the message that is received.

Preferably, comprise further between steps A and the B whether the message that judge to receive meets the access protocol requirement, if, execution in step B then, otherwise abandon the message that is received.

Described recorder state comprises that it is a count value that described accepting state is set.

Described periodic refreshing accepting state comprises, periodically count value is successively decreased, and describedly judges whether that the user who does not receive from the user for a long time asks back message using or user response response message to comprise, judges whether count value arrives predetermined threshold value.

Described step C further comprises, sends the request back message using by control module to the user.

Described accepting state is stored in user status table.

The present invention compared with prior art, have following characteristics: prior art receiving-transmitting chain detection messages all is to be finished by the software that operates on the control module CPU, data message of every reception, CPU just need read a complete data message from external equipment, and this process need take hundreds of instruction cycles; And the present invention is by accelerating module receiving-transmitting chain detection messages independently, and the CPU of control module only needs know from the message accepting state whether link is normal, needn't read whole data message, only need take several instruction cycles of CPU to the processing of each data message.Therefore, the load of CPU when the present invention can effectively reduce access server and carries out link detecting, thus improve the performance of system, the robustness of enhanced system.

Description of drawings

Fig. 1 is a prior art link detecting schematic diagram.

Fig. 2 is a link detecting schematic diagram of the present invention.

Fig. 3 handles the flow chart of message for accelerating module.

Embodiment

Because in the prior art, control module is not only handled the control message from the user in the access server, and handle the link detection message between access server and the user.In order to reduce the CPU burden of control module in the access server, the present invention comes the handle link detection messages by an accelerating module, and control module judges by the link detection message accepting state of record whether link is normal.Below be that example describes the present invention in detail with the ppp link state-detection.

Referring to shown in Figure 2, Fig. 2 is principle of the invention figure.Accelerating module receives the request back message using from the user, it is the LCP-Echo-Request message, simultaneously to the LCP-Echo-Request message, can return the response response message, it is the LCP-Echo-Reply message, further, can also receive user's LCP-Echo-Reply message, accelerating module receives the laggard line item of above-mentioned message.This accelerating module available hardware realizes that also available software realizes, preferably, for reducing the burden of CPU, adopts hardware to realize.A control module processing controls message also can send the LCP-Echo-Request message of access server to the user according to the needs of using, and for example, sends termly by ppp protocol, sends in also can be at the cpu load of control module lighter.

Accepting state for ease of record and inquiry link detection message, set up a user status table, the number of record is consistent with the number of users of access in this table, the corresponding user of each record, contents in table comprises: be used to indicate the current Link State item of opening (opened) state that whether is in of ppp link of user's correspondence, be used to indicate the LCP-Echo-Request that whether receives respective user recently or the link detection message accepting state item of LCP-Echo-Reply message.For example, " Link State " in the list item uses a bit, and ' 1 ' expression link is in the opened state, and ' 0 ' expression link is in the closed state; " link detection message accepting state " do not receive user's LCP-Echo-Request or LCP-Echo-Reply message recently with two bits, " 00 " expression, and other value representations received.All the elements of list item all will be by clear 0 when system reset is initialized.

Referring to shown in Figure 3, Fig. 3 handles the flow chart of message for accelerating module.Its concrete steps are as follows:

Step 301, in order to guarantee that user status table reflects the information that is write down in real time, user status table is refreshed, when refresh time then, execution in step 302, whether " the link detection message accepting state " of checking each user in the user status table is " 00 ", if certain user's is not " 00 ", then " the link detection message accepting state " with this user in the user status table subtracts 1; To " link detection message accepting state " be " 00 " do not make any modification, so circulation, all records are refreshed in user status table.When refresh time not then, then execution in step 303;

Step 303 judges by accelerating module whether the message of being received is link detection message, if then execution in step 304, otherwise end process;

Step 304 is extracted user profile from link detection message, and searches user status table according to user profile;

Step 305 judges according to the Link State item of user status table whether user link is in open mode, if execution in step 306 then, otherwise abandon this message;

Step 306 judges whether link detection message meets the requirement of PPP access protocol, if execution in step 307 then, otherwise abandon this message;

Step 307, the link detection message accepting state of this user in the user status table is provided with a count value, judge whether not receive for a long time link detection message with variation by count value, for example, it is 11 that the link detection message accepting state is set, and when whenever once refreshing, the link detection message accepting state subtracts 1, when the link detection message accepting state is 00, then show reducing to the link detection message that did not receive the user in 3 refresh cycles of 00 from 11;

Step 308 judges whether the link detection message of receiving is user's LCP-Echo-Request message, if, then act on behalf of control module and send the LCP-Echo-Reply message to the user, otherwise end process.

Because the foundation and the maintenance of ppp link realize by state machine, according to the RFC1661 agreement, a state machine comprises 10 states, control module is that each user (corresponding user's ppp link) distributes a state machine, when the state machine of user's correspondence is in the Opened state, the Link State item is set to ' 1 ', otherwise is set to ' 0 ', and the state machine result record according to user's ppp link correspondence is touched in the Link State item control of above-mentioned user status table.

Control module periodically reads link detection message accepting state in the user status table, judge whether corresponding user does not send LCP-Echo-Request and LCP-Echo-Reply message to access server for a long time, if, judge that then link is undesired, and determine whether and to send the LCP-Echo-Request message to the user, perhaps whether need to remove user's ppp link, otherwise judge that link is normal.

The above only is preferred embodiment of the present invention, and in order to restriction the present invention, the present invention not can be applicable to other detections yet.Whether for example, utilize ARP bag (or PING bag) to detect a user online; Under the Portal authentication mode, server is to user's detection; Detect online data (Detecting Data Plane Liveliness in MPLS) in the mpls protocol draft, it is identical that principle detects with this ppp link.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1, a kind of detection method of Link State is characterized in that, an accelerating module that is independent of control module hardware of living in is set, and this method may further comprise the steps:

2, detection method as claimed in claim 1, it is characterized in that, described step C further comprises, described accepting state by each user's correspondence of accelerating module periodic refreshing, control module judges whether that according to described accepting state the user who does not receive from the user for a long time asks back message using or user response response message, if judge that link work is undesired, otherwise, judge that link is normal.

3, detection method as claimed in claim 1 or 2, it is characterized in that, steps A further comprises, receive after the user asks back message using or user response response message, ask to extract user profile back message using or the user response response message from the user, whether the link of checking the user according to user profile is in open mode, if execution in step B then, otherwise abandon the message that is received.

4, detection method as claimed in claim 1 or 2 is characterized in that, further comprises between steps A and the B, and whether the message that judge to receive meets the access protocol requirement, if, execution in step B then, otherwise abandon the message that is received.

5, detection method as claimed in claim 2 is characterized in that, described recorder state comprises that it is a count value that described accepting state is set.

6, detection method as claimed in claim 5 is characterized in that,

Described periodic refreshing accepting state comprises, periodically count value successively decreased,

Describedly judge whether that the user who does not receive from the user for a long time asks back message using or user response response message to comprise, judges whether count value arrives predetermined threshold value.

7, detection method as claimed in claim 1 is characterized in that, described step C further comprises, sends the request back message using by control module to the user as required.

8, detection method as claimed in claim 1 is characterized in that, described accepting state is stored in user status table.