CN1297127C - Treating method for connection release between nodes based AAL2 signalling protocol - Google Patents

Abstract

The invention relates to a processing method for connection release between nodes based on AAL2 signaling protocol. The present invention directly releases the occupied protocol entity and corresponding resource information when the node based on the AAL2 signaling protocol receives the RLC message sent by the opposite end, instead of only when the local end connection is in the unfinished state of outgoing release, The occupied connection resources are only released when the release conflict state or the outbound establishment is not completed. The realization of the invention ensures that the system can still recover to normal quickly when the AAL2 signaling protocol is abnormal, and effectively avoids the normal communication of the system being affected by the abnormality. Therefore, the implementation of the present invention improves the reliability and stability of the communication system.

Description

Processing method of connection release between nodes based on AAL2 signaling protocol

technical field

The invention relates to the technical field of network communication, in particular to a processing method for releasing connection between nodes based on AAL2 signaling protocol.

Background technique

The AAL2 (ATM Adaptation Layer 2) signaling protocol provides the function of establishing, releasing and maintaining an AAL2 connection between two nodes in order to carry user data on the AAL2 connection. address) standards have been widely used.

The main flow of the signaling protocol is as follows, see Figure 1 and Figure 2:

The establishment initiator (node 1) selects the appropriate channel resource CEID (AAL2 connection unit identifier) according to the destination address and routing configuration, including the path (Path) and channel (Channel), and sends the establishment request message ERQ to the adjacent node (node 2) , the ERQ message not only includes channel resource, destination address and resource attributes and other related information, but also includes OSAID (Source Signaling Connection Identifier), which is allocated by the message sender and is used to identify the corresponding protocol entity of the message sender.

After the adjacent node receives the establishment request message ERQ, it checks the validity of the CEID and whether it meets other access conditions. If it is correct, the protocol entity at this end enters the establishment success state (Established state), and saves the OSAID in the ERQ message as a DSAID to Locally, the establishment confirmation message ECF is sent back to the originator. The ECF contains the OSAID allocated by the local end, and fills in the message header with the OSAID of the opposite end as the DSAID (destination signaling connection identifier) of the local end.

The initiator of the protocol receives the establishment confirmation message ECF, saves the OSAID in the message locally as the DSAID, and enters the establishment success state (Established state).

When the release originator releases, it sends a release message REL to the opposite end, and the message contains a DSAID and a cause value. The signaling protocol entity at the local end enters the release sending state (Outgoing Release Pending state).

When the release receiving end receives the REL message, it converts the DSAID in the message into the OSAID of the local end. Since the value is allocated by the local end, it is easier to find the protocol entity of the local end, release the protocol entity and OSAID, and send it to the release initiator Release complete message RLC with DSAID in the message.

During the communication process, it is possible that the signaling protocol entities at both ends send the release message REL at the same time, so it is possible to receive the release message REL from the peer end before receiving the release complete message RLC from the peer end after sending the release message. At this time, the protocol entity Enter the release conflict state (Release Collision state), at this time both ends are release initiators.

When the release initiator receives the RLC, it converts the DSAID in the message into the OSAID of the local end, finds the protocol entity of the local end according to the value, and checks whether the protocol entity is in the outgoing release pending state and the release collision state (release collision) status), if yes, release the protocol entity and OSAID, otherwise discard the message.

At the same time, when the local end receives the RLC message, if the local end is in an incomplete state of outbound setup, it also needs to release the protocol entity and OSAID.

The above processing flow for the node when receiving the RLC message can release the protocol entity and corresponding resource information occupied by the corresponding connection as required under normal circumstances. However, the communication system does not always work under normal conditions. For example, when the inconsistency between the two ends of the connection occurs, one end releases the protocol entity and resource information occupied by the connection abnormally for some reason, but the other end does not work due to various reasons. If the release message is not received, the connection is still kept in a normal state. At this time, the OSAID of the end of the released connection may be used by other connections normally, resulting in an abnormal situation.

The following is a further description of the possible consequences of the abnormal situation. As shown in Figure 3, the DSAID of protocol entity 1 in node 2 in connection a points to entity 1 of node 1, and protocol entity 1 of node 1 is abnormal Released and reused in connection b, whose DSAID points to entity 3 of node 2. When entity 1 of node 2 initiates the release of connection a, entity 1 of node 1 is released, and the OSAID is released and reused in connection c, causing entity 1 of node 1 to point to entity 5 of node 2, and at the same time causing connection b The function is not normal. Similarly, when entity 3 of node 2 is released, entity 1 of node 1 is released again, and the OSAID is released and reused in connection d, which causes connection c to function abnormally.

From the above description of the possible consequences of the abnormal situation, it can be seen that once a connection is abnormal, it will cause other connections to be abnormal in a chain. The root cause of this situation is that there are only DSAID and reason parameters in the REL message. When an illegal REL message comes, the source of the message cannot be verified and can only be released unconditionally. The OSAID will be used in the subsequent process. Other new On the established connection, at the same time, send an RLC message to the opposite end according to the DSAID of the opposite end recorded by the local end. When the opposite end receives the RLC message, if it finds that it is not the release sending end, that is, it is not in the release sending state (outgoing release pending state) and If the release conflict state (release collision state) is not in the state that the outbound establishment is not completed, the message will be discarded without processing, and the protocol entity will not be released at this time, which will cause one end of the protocol entity at both ends of the connection to be released while the other end does not Release, the released protocol entity will be used by other connections to establish a new connection, and if the unreleased end actively releases the connection, it will cause the abnormal release of the newly established connection at the opposite end, eventually causing the system to fail to communicate normally.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a processing method based on the connection release between nodes of the AAL2 signaling protocol, so as to effectively avoid the problem of chain release in the communication system, thereby improving the reliability of the system communication. stability and reliability.

The purpose of the present invention is achieved through the following technical solutions:

The present invention provides a processing method for inter-node connection release based on the AAL2 signaling protocol, including: when a node based on the AAL2 signaling protocol receives a connection release completion message from the opposite end, if the local end is in the incoming release pending Completed, Incoming Establishment Incomplete, Established, Outgoing Modification Incomplete, Modification Conflict, or Incoming Modification Incomplete, the connection resources occupied by the connection will also be released.

The connection resource occupied by the connection includes: the protocol entity occupied by the connection and corresponding resource information.

The processing method for releasing the connection between nodes based on the AAL2 signaling protocol further includes: after releasing the connection resource occupied by the connection, the local end turns into an idle state.

The present invention also provides a processing method for inter-node connection release based on the AAL2 signaling protocol. In the method, when a node based on the AAL2 signaling protocol receives a connection release completion message from the opposite end, it is judged whether the local end In the idle state, if it is in the idle state, no processing is required, and if it is not in the idle state, the connection resources occupied by the connection are directly released.

The connection resource occupied by the connection includes: the protocol entity occupied by the connection and corresponding resource information.

The corresponding resource information includes the source signaling connection identifier OSAID.

The processing method for releasing the connection between nodes based on the AAL2 signaling protocol further includes: after releasing the protocol entity and corresponding resource information occupied by the connection, the local end turns into an idle state.

As can be seen from the technical solution provided by the present invention above, the present invention directly releases the occupied protocol entity and corresponding resource information when the node based on the AAL2 signaling protocol receives the RLC message sent by the opposite end, instead of Only when the local connection is in the state of outgoing release incomplete, release conflict state, or outgoing establishment incomplete state, the occupied connection resources are released, which ensures that the system can quickly return to normal when the AAL2 signaling protocol is abnormal. This abnormality can effectively avoid the normal communication of the system. Therefore, the implementation of the present invention improves the reliability and stability of the communication system.

Description of drawings

Fig. 1 is the basic flow of the AAL2 signaling protocol without release conflict and modification conflict state;

Fig. 2 is the basic flow of the AAL2 signaling protocol that releases conflicts and modifies conflicting states;

Figure 3 is an entity relationship diagram of connection release when an abnormal situation occurs;

Figure 4 is a schematic diagram of the method of the present invention.

Detailed ways

The core idea of the present invention is to modify the standard AAL2 signaling protocol on the basis of the process of releasing the connection, which reduces the status constraints of the protocol entity and the corresponding resource information occupied by the release connection, that is, when receiving the When the release completion message is sent from the end, if the local end is not in the state of outgoing release incomplete, release conflict state, or outgoing establishment incomplete state, it can still perform the operation of releasing connection resources according to actual needs, thus ensuring that when two connections are connected When an exception occurs at the end, the occupied protocol entities and corresponding resources can still be reliably released, so that the communication system can return to normal in a relatively short period of time.

When one of the two ends of the connection based on the AAL2 signaling protocol releases the protocol entity and corresponding resource information occupied by the connection abnormally, the other end may usually be in the following states: Incoming release pending, incoming establishment Incoming establishment pending, established, outgoing modify pending, modify collision or incoming modify pending. In the present invention, in order to ensure that both ends of the communication can release the occupied connection resources within a certain period of time and avoid the problem of chain release, it is necessary to release the connection resources occupied by the connection when an abnormal situation occurs at one of the two ends of the communication. , the other end will also release the connection resources occupied by the connection after receiving the release completion message from the end where the abnormal situation occurs. The connection resource occupied by the connection includes: the protocol entity occupied by the connection and corresponding resource information. Corresponding resource information includes OSAID

For this reason, in the present invention, when receiving the release completion message sent by the opposite end, it is judged that the connection of the local end is in a specific state, and then according to the needs of connection release, the protocol entity and corresponding resources ( That is, the occupied connection resource) is released, and the specific state can be one of the incoming release unfinished state, incoming establishment unfinished state, established state, outgoing modification unfinished state, modification conflict state, and incoming modification unfinished state species, multiple or all. For example, assuming that the specific state includes the incomplete establishment state and the established state, then when the local end receives the release completion message sent by the peer end, it judges whether the local end connection is in the incoming establishment incomplete state or established state, if If yes, release the connection resources occupied by the connection. After the connection resource occupied by the connection is released, the local end enters the idle state.

If the selection of the specific state is all, then the technical scheme that the present invention can also adopt is: after the end receives the release completion message sent by the opposite end, only judge whether the end is in the idle state, if in the idle state ( That is, no protocol entities and corresponding resources are occupied), there is no need to perform any processing, and if they are not idle, the occupied protocol entities and corresponding resources are released directly.

That is to say, in the present invention, when the node receives the release completion message from the opposite end, it indicates that the opposite end has released its protocol entity and corresponding resources, so the protocol entity and corresponding resources of the local end should also be released accordingly. Therefore, at this time, even if the protocol entity is not in the outgoing release pending state, release conflict state, or outgoing setup pending state, it is in the incoming release pending state, incoming setup pending state, established state, outgoing modification pending state, Modifying the conflict state or inbound modification of the incomplete state also needs to release the protocol entities and corresponding resources (such as OSAID information) occupied by the connection. That is, as shown in Figure 4, when the local end receives the release completion message sent by the opposite end, it judges whether the local end connection is in the state of outgoing release incomplete, release conflict state, outgoing call establishment incomplete state, inbound release incomplete state, Incoming setup unfinished state, established state, outgoing modification unfinished state, modification conflict state or incoming modification unfinished state, if yes, release the connection resources occupied by the connection, otherwise, do nothing.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (8)

1, a kind of based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that this method comprises, when receiving the connection Release complete of sending the opposite end based on the node of atm adaptation layer 2 AAL2 signaling protocol, Incoming discharges unfinished state, Incoming is set up unfinished state, established state, out unfinished state, modification conflict situation or the Incoming modification unfinished state revised if local terminal is in, and then also will discharge the connection resource that this connection takies.

2, according to claim 1 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that the connection resource that described connection takies comprises:

Protocol entity that this connection takies and corresponding resource information.

3, according to claim 2 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that described corresponding resource information comprises source signaling connection identifier OSAID.

4, according to claim 1 and 2 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that also comprising:

Local terminal changed idle condition over to after release connected the connection resource that takies.

5, a kind of based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that, when receiving the connection Release complete of sending the opposite end based on the node of AAL2 signaling protocol, judge whether local terminal is in idle condition, if be in idle condition, then need not to handle,, then directly discharge the connection resource that this connection takies if be not in idle condition.

6, according to claim 5 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that the connection resource that described connection takies comprises:

Protocol entity that this connection takies and corresponding resource information.

7, according to claim 6 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that described corresponding resource information comprises source signaling connection identifier OSAID.

8, according to claim 5 based on connecting the processing method that discharges between the node of AAL2 signaling protocol, it is characterized in that this method also comprises:

Local terminal changes idle condition over to after protocol entity that the release connection takies and the corresponding resource information.

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