CN101146094A

CN101146094A - A method for quick release of failed links at transmission signaling L2 peer adaptation layer

Info

Publication number: CN101146094A
Application number: CNA2006101271612A
Authority: CN
Inventors: 梁庆永
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2006-09-08
Filing date: 2006-09-08
Publication date: 2008-03-19
Also published as: WO2008031290A1

Abstract

The invention discloses a link failure fast dismantling method of a transmission signaling second layer peer-to-peer adaptation layer, which relates to a link failure fast dismantling method in IP network signaling transmission protocol, which can solve the problem that a timer mechanism is adopted when a M2PA protocol entity receives a missequence information unit in the prior protocol and requires longer time for link failure dismantling,. The method of the invention is to actively initiate signaling channel release operation by the M2PA protocol entity receiving the missequence information unit, effectively avoids the longer time for the link failure dismantling for packet loss and missequence in the prior protocol, reduces the dismantling time to millisecond level and is applicable to the communication equipments with high timeliness requirement.

Description

The method of two layers of reciprocity adaptation layer quick release of failed links of a kind of command transmitting

Technical field

The present invention relates to IP network signaling transfer protocol (SIGTRAN), relate in particular to the method for a kind of quick dismounting fault signaling link of MTP2 equity adapting protocol (M2PA agreement) when abnormal conditions such as packet loss incorrect order take place.

Background technology

Along with the progressively maturation of IP network technology, the demand of circuit switching signaling protocols such as Signaling System Number 7 has appearred transmitting on IP network.In order to satisfy the demand in IP network transmitting signaling agreement, the IETF network work is formed the special signaling transmission group of having stood, and the IP network signaling transfer protocol (SIGTRAN) that they worked out is supported by IP network transmission legacy circuit-switched signaling.IETF working group had formally issued MTP2-User Peer-to-Peer Adaptation Layer agreement (M2PA in 2005, MTP2 Peer to PeerAdaption Layer), the M2PA agreement is used for realizing being carried between two MTP3 peer protocol entities on the IP network the reliable of message and transmits in order.China Ministry of Information Industry in 2002 have also formally issued the communication industry standard of M2PA.The concrete protocol architecture of M2PA is shown in accompanying drawing 1, accompanying drawing 2.

M2PA is for two layers directly to be carried on Stream Control Transmission Protocol (RFC2960) entity as the command transmitting in the IP network, and the Stream Control Transmission Protocol entity has possessed the reliable characteristic of transmission in order.Therefore in RFC consensus standard and Communication in China industry standard, all the reliable transmission mechanism in order of M2PA is not further described.But M2PA is the reliable transmission in order of finishing message between the MTP3 protocol entity by Stream Control Transmission Protocol entity and M2PA protocol entity jointly as the command transmitting link layer that is under the MTP3 protocol entity.If when packet loss, error situation such as out of order have taken place two peer protocol inter-entity of SCTP, can guarantee that the recovery of sequence number is synchronous by mechanism such as re-transmissions in the IP network transmission course in the Stream Control Transmission Protocol inter-entity.But when abnormal conditions such as M2PA protocol entity and Stream Control Transmission Protocol inter-entity generation information drop-out, message receiver M2PA protocol entity can be abandoned the data message of the discontinuous sequence number that transmit leg M2PA protocol entity sends over always, so and message sender M2PA protocol entity since the information drop-out situation that takes place before unclear can continual transmission message to M2PA recipient's protocol entity.These abnormal conditions last till that always transmit leg M2PA protocol entity detects the long-time no response of packet loss message and causes sending Out ofService (withdrawing from service) to recipient M2PA protocol entity.Carry out the MTP3 data subsequently and return and get and the switching operation of signaling link, under the serious situation even may cause abnormal conditions such as the signaling office direction is unreachable.These abnormal conditions are described referring to accompanying drawing 3.And for the packet loss incorrect order of M2PA peer protocol inter-entity, signaling link is bound to take place the link hit, but present testing mechanism is to rely on the timer of replying of message sender to come detection time longer relatively, is generally about second rank.

Summary of the invention

In order to overcome above-mentioned defective, the object of the present invention is to provide the method for two layers of reciprocity adaptation layer quick release of failed links of a kind of command transmitting, this method has solved and has received out-of-sequence MSU at the M2PA protocol entity and needing to cause the long period to remove the faulty link problem.

For achieving the above object, the method for two layers of reciprocity adaptation layer quick release of failed links of a kind of command transmitting of the present invention, the M2PA protocol entity that receives out-of-sequence Message Signal Unit is initiatively initiated the release signaling link operation.

The method that the described M2PA protocol entity that receives out-of-sequence message elements is initiatively initiated the release signaling link operation is specially:

(1) the M2PA protocol entity transmission value that receives out-of-sequence Message Signal Unit is given the M2PA protocol entity that sends out-of-sequence Message Signal Unit for the LSSU Link Status Signal Unit of " withdrawing from service ";

(2) the M2PA protocol entity that receives out-of-sequence Message Signal Unit reports signaling link to withdraw from service to upper-layer user MTP3, puts the signaling link state simultaneously for withdrawing from service state;

(3) the M2PA protocol entity that sends out-of-sequence Message Signal Unit receives value that the M2PA protocol entity that receives out-of-sequence Message Signal Unit sends for behind the LSSU Link Status Signal Unit of " withdrawing from service ", sends the M2PA protocol entity termination timing device of out-of-sequence Message Signal Unit;

(4) the M2PA protocol entity of the out-of-sequence Message Signal Unit of transmission reports signaling link to withdraw from service to upper-layer user MTP3, puts the signaling link state simultaneously for withdrawing from service.

The method of two layers of reciprocity adaptation layer quick release of failed links of a kind of command transmitting provided by the invention, it is the improvement that the M2PA related protocol is received the handling process of out-of-sequence MSU about M2PA, by initiatively send LSSU (Link State Signal Unit, LSSU Link Status Signal Unit) in the M2PA protocol entity side that receives out-of-sequence MSU: Out of Service comes the release signaling link.Avoided in the present agreement realization in case the out-of-sequence situation of packet loss occurs, the packet loss of two second time and chain rupture dismounting nearly; Having solved the M2PA protocol entity receives out-of-sequence message elements and must cause the M2PA signaling link to interrupt and needs long period detects at interval that signaling link interrupts and with the problem of faulty link dismounting.Farthest prevent losing of M2PA protocol entity upper-layer user data, guarantee the quick dismounting of fault signaling link from flow process.Method flow provided by the present invention will be removed the faulty link time interval and shorten to a millisecond rank.For real-time required very high communication apparatus, this temporal improvement was necessary.

Description of drawings

Fig. 1 is the protocol stack that M2PA uses in IPSP;

Fig. 2 is the protocol stack that M2PA uses in SG;

Fig. 3 is that the post and telecommunications consensus standard of the RFC agreement of present M2PA and M2PA is about the out of order fault processing flow process of M2PA;

Fig. 4 is the flow chart that the present invention passes through initiatively to send LSSU:Out of Service release signaling link.

Embodiment

The present invention initiatively initiates the release signaling link operation by the M2PA protocol entity that receives out-of-sequence message elements, needs the problem that a long period removes faulty link at interval when avoiding signaling link to interrupt., be further described in detail the method that the present invention passes two layers of reciprocity adaptation layer quick release of failed links of elm signaling below in conjunction with accompanying drawing 3 and Fig. 4.

As shown in Figure 3, in present M2PA agreement, M2PA protocol entity _ second sends MSU to M2PA protocol entity _ first, (wherein: MSU is a Message Signal Unit Message Signal Unit owing to the MSU:FSN=7 BSN=6 that does not receive M2PA protocol entity _ second for M2PA protocol entity _ first, FSN is a Forward Sequence Number forward sequence number, and BSN is to sequence number behind the Backward Sequence Number.FSN represents the numbering of the Message Signal Unit that current sender M2PA protocol entity sends, the numbering of the current Message Signal Unit that receives from opposite end M2PA protocol entity of BSN representative) so can abandon the MSU that M2PA protocol entity _ second of receiving subsequently sends over always.This situation can last till the MSU:FSN=7 BSN=6 packet wait acknowledge timer Timer T7 of M2PA protocol entity _ second correspondence overtime (concrete handling process is referring to relevant M2PA agreement) always, sends LSSU:Out of Service to M2PA protocol entity _ first and begins the release signaling link.Describe and to find from the agreement flow process,, will inevitably cause the release of M2PA signaling link in case it is out of order that packet loss takes place between the M2PA protocol entity.And the time interval of the dismounting of faulty link must abandon if M2PA protocol entity upper-layer user message elements flow-rate ratio can cause lot of data to wrap in M2PA peer protocol inter-entity when big in the Timer T7 time interval.

Be bound to take place chain rupture as long as out-of-sequence situation signaling link occurs under the protocol at present.The present invention improves the existing protocol described in the accompanying drawing 3, initiatively send LSSU:Out of Service (withdrawing from service) when as shown in Figure 4, detecting the message elements that receives out-of-sequence FSN and come the release signaling link by receiving terminal M2PA protocol entity.The present invention removes out-of-sequence fault signaling link rapidly as far as possible, and concrete steps are as follows:

Step 101:M2PA protocol entity _ first receives out-of-sequence message elements MSU;

Step 102:M2PA protocol entity _ first sends LSSU:Out of Service to M2PA protocol entity _ second;

Step 103:M2PA protocol entity _ first reports signaling link to withdraw from service to upper-layer user MTP3, and it is Out of Service that M2PA protocol entity _ first is put the signaling link state;

Step 104:M2PA protocol entity _ second receives the LSSU:Out of Service that M2PA protocol entity _ first sends, and M2PA protocol entity _ second stops Timer T7;

Step 105:M2PA protocol entity _ second reports signaling link to withdraw from service to upper-layer user MTP3, and putting the signaling link state simultaneously is Out of Service.

The method of two layers of reciprocity adaptation layer quick release of failed links of a kind of command transmitting provided by the invention, be to the M2PA related protocol about the improvement that M2PA receives the handling process of out-of-sequence MSU, come the release signaling link by initiatively sending LSSU:Out of Service in the M2PA protocol entity side that receives out-of-sequence MSU.Avoided in the present agreement realization in case the out-of-sequence situation of packet loss occurs, the packet loss of two second time and chain rupture detection nearly; Having solved the M2PA protocol entity receives out-of-sequence message elements and must cause the M2PA signaling link to interrupt and needs long period is detected the problem of signaling link interruption at interval.Prevent losing of M2PA protocol entity upper-layer user data to the full extent, guarantee the quick dismounting of fault signaling link from flow process.The time interval that method flow provided by the present invention will be removed faulty link shortens to a millisecond rank.For real-time required very high communication apparatus, this temporal improvement was necessary.

Claims

1. the method for two layers of reciprocity adaptation layer quick release of failed links of a command transmitting is characterized in that, the M2PA protocol entity that receives out-of-sequence Message Signal Unit is initiatively initiated the release signaling link operation.

2. the method for two layers of reciprocity adaptation layer quick release of failed links of command transmitting as claimed in claim 1 is characterized in that, the method that the described M2PA protocol entity that receives out-of-sequence message elements is initiatively initiated the release signaling link operation is specially: