CN1878136A

CN1878136A - Method for recognizing multiple emulation service flow path

Info

Publication number: CN1878136A
Application number: CN200610033335.9A
Authority: CN
Inventors: 张华琛; 吕华明; 乔剑
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-01-23
Filing date: 2006-01-23
Publication date: 2006-12-13
Anticipated expiration: 2026-01-23
Also published as: WO2007082424A1; CN100433722C

Abstract

The invention discloses an identifying method of multi-path artificial business flow path, which is characterized by the following: setting AC-id item to identify specific sub-accessory circuit (AC) business when the allocating accessory circuit NTO1 pattern PW binds order; increasing AC-id field and corresponding transferring index in the sent report; mating sub-AC according to AC-id after receiving report; distributing hardware transferring table when one business flow aligns double-terminal AC and PE of UP; transferring the business report; otherwise, blocking to transfer business report. The invention adopts AC-id transferring index field to replace VPI/VCI field to identify one PVC specifically to transfer, which improves the transferring speed.

Description

A kind of method for recognizing multiple emulation service flow path

Technical field

The present invention relates to communication technical field, relate in particular to a kind of method for recognizing multiple emulation service flow path based on PWE3 (the pseudo-end to end circuit emulation of Pseudo-WireEmulation Edge-to-Edge).

Background technology

At present operator is when providing multiple business, employing substantially all be the mode of parallel or " overlapping ": set up and safeguard multiple network, presenting a little at every kind of different different access device of business use.Do like this except making the network planning more the complexity, and be that construction cost or operation cost are all very expensive.So operator when multiple business is provided, builds and operation cost in order to reduce, and wishes to seek a kind of method that multiple business can be provided on public packet network (PSN).

For unified multibusiness network platform is provided, IETF has begun the standardization effort of on packet network " the X over PSN " of any business of transmission, and the pseudo-end to end circuit emulation of its called after (Pseudo-Wire Emulation Edge-to-Edge is abbreviated as PWE3).

The realization of artificial service can be divided into two kinds on packet network: PSN only carries an emulation service flow (1 TO, 1 mode) and a PSN carries multiple emulation service flow (N TO 1 mode).Article one, to carry the benefit of multiple emulation service flow be can more effective use PW (pseudo-line) head to PSN.

The foundation of PW is the result that two ends PE (Provider Equipment service provider equipment) consults mutually, so two ends PE wants mutual local PW forwarding state.The forwarding state of local PW depends on the state of the outer layer tunnel of the state of the state of the AC business that need carry out emulation and the LDP session of far-end PE (LDP session) and carrying pseudo-line service.And the professional state of AC (Attachment Circuit accessory circuit) depends on that the summation of the N strip AC state of this PW correspondence (in the network model of agreement is collectively referred to as the multiple pvcs (connection of Permanent Virtual Connect permanent virtual) of binding same PW under N TO 1 mode simultaneously an AC under N TO 1 mode, the present invention defers to the title method in the protocol network model, but in order to set forth conveniently, one " the sub-AC " that a PVC among the AC under NTO 1 mode is called this AC): if in many strips AC of PW correspondence, the last item state is that the sub-AC DOWN (abnormal operating state) of UP (normal operating conditions) falls, and then the state of AC is DOWN; The first strip ACUP among the sub-AC of all of PW correspondence, then the state of AC is UP.The mode of announcement has two kinds: the announcement of the Notification mode of the announcement of Martini mode and expansion.

1, the announcement of Martini mode:

Referring to Fig. 1, the state of the 1dp session of the state of AC and far-end PE and the state of outer layer tunnel be UP simultaneously, and then the forwarding state of local PW sends the Mapping message for transmitting; If there is a DOWN to fall among the three, then the forwarding state of local PW is for transmitting, and will send the Withdraw message this moment, regain vpn label.As: under the situation of PW UP, as long as AC DOWN, then the forwarding state of local PW sends the Withdraw message for transmitting, and removes agreement.

2, the announcement of Notification mode:

After sending the mutual vpn label of Mapping, as long as configuration is not deleted, agreement is not just removed, and only sends Notification interacting message both sides' local PW state.As: under the situation of PW UP, as long as AC DOWN, then the forwarding state of local PW is for transmitting, but do not send out the Withdraw message and remove agreement this moment, announce the forwarding state of the local PW of the other side for can not transmit (realizing) and just send the Notification message by the forwarding sign indicating number of announcing local PW, keep vpn label, as shown in the figure, comprise the conditional code of local PW in the Notification message.

The state that Mapping (label mapping) message that whether sends mutual vpn label under the Martini mode depends on the state of session of the state of AC and opposite end PE and outer layer tunnel is UP simultaneously.And regain vpn label as long as the state of the state of the session of the state of AC and opposite end PE and outer layer tunnel has a DOWN to fall just to send the Withdraw message.The back needs only and the state UP of the session of opposite end PE and be configured under the Notification mode, and regardless of the state of AC or the state of outer layer tunnel, just sends the Mapping message of mutual vpn label.When the state of AC or the state DOWN of outer layer tunnel fall, just upgrade local PW conditional code, and the opposite end PE of local PW conditional code by Notification message announcement, mainly be as long as configuration is not deleted with the difference of Martini mode, it is not just removed agreement and reclaims vpn label, announce local PW state for can not forwarding state and just send the Notification message, next time is again during UP, do not need the label of reallocating again, just send the Notification message again and announce local PW forwarding state for transmitting.

Prior art Notification mode has an enormous advantage than Martini mode and is, it can reduce the mutual of message packet between the PE.But their a common deficiency point is: can't announce the professional right information of concrete AC.As shown in Figure 3, wherein subAC1-subAC3 and subAC2-subAC4 are respectively two Business Streams, adopt the multiplexing pseudo-line PW1 of mode of N TO 1.SubAC1 inserts the different port of PE1 respectively with subAC2, and both combinations of states form the AC state at PE1 place.SubAC3 inserts the different port of PE2 respectively with subAC4, and combinations of states forms the AC state at PE2 place.At the PE1 place, during with the state UP of the state UP of the LDP session of far-end PE and outer layer tunnel, if the subAC1 state becomes UP by DOWN, then the AC state at PE1 place is with regard to UP, this moment, but local PW forwarding state was a forwarding state, perhaps send the Mapping message, perhaps send the Notification message and announce local PW state UP.At the PE2 place, with the state of the session state of opposite end PE and outer layer tunnel all during UP, if the subAC4 state becomes UP by DOWN, then the AC state at PE2 place is with regard to UP, but the local PW forwarding state of PE2 this moment also is a forwarding state, because the PW forwarding state of local and far-end all is to transmit, the state of this PW is UP, issues the logical forwarding list item.But actual conditions are subAC1 and subAC3, and to be only a business right, so after the business information of subAC1 arrived PE2 by PW1, because subAC3 state DOWN, the service message of subAC1 still can be abandoned by PE2.This shows, under this situation, be that Martini mode or Notification mode all can't be announced the correct business of AC to information, the business information of subAC1 can not finally be forwarded to the destination after arriving PE2 by PW1, strengthened the processing burden of node on the way in rain, what is more important has been wasted valuable network bandwidth resources.

Prior art is for the concrete message encapsulation format of PW business under N TO 1 mode, is that example is done concrete elaboration with the N TO 1 message encapsulated frame form of ATM, and the encapsulation of other business is similar substantially.Come N TO 1 ATM PW message frame is encapsulated with the encapsulation format shown in Fig. 4,5, by in the message with vpi/vci distinguish concrete AC.Stipulate in the agreement: the vpi/vci value that guarantee the PVC of different port has nothing in common with each other.But in actual applications, this point is to be difficult to guarantee.Therefore need come the vpi/vci value of the next PVC of each port is carried out a conversion by outvpi/outvci, accomplish that the overall situation is unique.When receiving N TO 1 ATM PW message frame, search concrete PVC by outvpi/outvci, carry out the processing respectively of different business.

The limitation of existing mode is:

1) outvpi/outvci of the outgoing direction of corresponding PW is not necessarily identical with the value of going into inputvpi/inputvci under this mode, so Inbound and outgoing direction all need to dispose the bind command of PW and PVC:

a.PVC+PW+outvpi/outvci

b.inputvpi/inputvci+PW+PVC

Increased user configured complexity like this.

2) hardware is realized comparatively complexity, and search efficiency is lower.For Inbound, need obtain corresponding PVC according to the inputvpi/inputvci in the message.The scope of vpi/vci is respectively 12/16, but because 28 powers of the PVC number that general equipment is supported much smaller than 2, so on hardware, need to finish mapping with HASH.

Summary of the invention

Technical problem to be solved by this invention is: overcome prior art owing to can't announce the correct business of AC to message, cause PW state UP during the right AC UP of non-business, but PW can not really E-Packet again, even cause the AC information of an end to arrive the PE of the other end by the pseudo-line of PW, can not be continued to transmit, but abandoned by this PE, thereby waste the processing resource of node on the way and the defective of valuable network bandwidth resources, protocol optimization method under a kind of N TO 1 mode is provided, accurately know artificial service to information, and make the PW state consistent with real forwarding state.

The present invention solves the problems of the technologies described above the technical scheme that is adopted to be:

A kind of method for recognizing multiple emulation service flow path, described method comprises:

A, the pseudo-line bind command of the public simulated line mode of configuration accessory circuit many Business Streams are provided for identifying the accessory circuit identifier of sub-accessory circuit business;

B, the transmission of pseudo-line first end have the first accessory circuit identifier field and inform message;

C, pseudo-line second termination are received the described message of informing, seek the second sub-accessory circuit with identical described first accessory circuit identification field according to described accessory circuit identifier;

D, when the described second sub-accessory circuit and described pseudo-line normal operating conditions all, issue the hardware forwarding table item, transmit service message, otherwise do not transmit service message.

Described method, wherein, the described message of informing comprises: inform normal message and inform improper message.

Described method, wherein, described step B specifically comprises:

When the state of the first sub-accessory circuit of pseudo-line first end became normal operating conditions by abnormal operating state, this end first service provider's equipment sends informed normal message; Describedly inform that normal message carries the identifier of sub-accessory circuit and corresponding forwarding index.

Described method, wherein, described step C specifically comprises:

After second end, second service provider's equipment of pseudo-line receives and informs normal message, seek the second sub-accessory circuit according to described accessory circuit identifier with identical described first accessory circuit identification field.

Described method, wherein, described step D specifically comprises:

When the state of the second sub-accessory circuit is normal operating conditions, pseudo-line states is judged;

If pseudo-line is a normal operating conditions, then the state with the first terminal accessory circuit in second service provider's device data structure is changed to normal operating conditions, and issues the hardware forwarding table item, begins to transmit service message;

If pseudo-line is an abnormal operating state, the state of the first sub-accessory circuit in second service provider's device data structure is changed to normal operating conditions.

Described method, wherein, described step D also comprises:

When the state of the second sub-accessory circuit is abnormal operating state, the state of the first terminal accessory circuit in second service provider's device data structure is changed to normal operating conditions.

Described method, wherein, when the state of last sub-accessory circuit of pseudo-line first end became abnormal operating state by normal operating conditions, this end first service provider's equipment sends informed improper message; Describedly inform that improper message carries the identifier of sub-accessory circuit.

Described method, wherein, described step C also comprises step:

When second end, second service provider's equipment of pseudo-line receive inform improper message after, seek the second sub-accessory circuit with described first identical sub-accessory circuit identification field according to described accessory circuit identifier.

Described method, wherein, described step D specifically comprises:

When the state of the second sub-accessory circuit is normal operating conditions, judge whether pseudo-line states is normal;

When pseudo-line is a normal operating conditions, then the state with the first sub-accessory circuit in second service provider's device data structure is changed to abnormal operating state and deletes the hardware forwarding table item;

Otherwise only the state with the first sub-accessory circuit in second service provider's device data structure is changed to abnormal operating state.

Described method, wherein, adjust the pseudo-line encapsulated message form of many public simulated line modes of Business Stream, with the forwarding index field replacement identifier of the virtual route/virtual channel identifier field of accessory circuit identifier correspondence, permanent virtual of index sign connects.

Described method, wherein: described method also comprises:

Judge whether pseudo-line vpn label distributes; If the described label of the pseudo-line in service provider equipment two ends all distributes, then the state of pseudo-line is exactly a normal operating conditions, otherwise the state of pseudo-line is exactly an abnormal operating state.

Beneficial effect of the present invention is: can know accurately that by AC-id artificial service is to information, the PW UP that refusal causes owing to the right AC UP that do not belong to same artificial service, make PW state and real forwarding state strict conformance, avoided the finally business transmission of intercommunication to waste the processing resource and the valuable network bandwidth resources of node on the way, and the business configuration order of N TO 1 mode AC and PW binding is simple, half before configuration amount has only; Simultaneously, because adopting the forwarding index forwarding index field of AC-id to replace the VPI/VCI field specifically to identify a PVC transmits, therefore the hardware realization is simple relatively, can determine the information of concrete PVC by the index of linear search AC-id correspondence, thereby improves forwarding speed.

Description of drawings

The network diagram that Fig. 1 announces for the Martini mode;

The network diagram that Fig. 2 announces for the Notification mode; Fig. 3 is a PW network diagram under the prior art N TO1 mode;

Fig. 4 is prior art N TO 1 an ATM PW message frame encapsulation format schematic diagram;

Fig. 5 is the concrete encapsulation format schematic diagram of prior art N TO 1 ATM PW message frame;

Fig. 6 is PW network diagram under N TO 1 mode of the present invention;

Fig. 7 is N TO 1 mode lower network reference model figure of the present invention;

Fig. 8 is the concrete encapsulation format schematic diagram of N TO 1 ATM PW message frame of the present invention.

Embodiment

With embodiment the present invention is described in further detail with reference to the accompanying drawings below:

The agreement that the present invention relates generally to N TO 1 mode of artificial service on the packet network realizes, comprises following content: when configuration AC N TO 1 mode PW bind command, be provided for identifying AC-id (accessory circuit identifier) configuration item of concrete sub-AC business; In sending Notification (informing) message, increase AC-id field and corresponding forwarding index, after receiving the Notification message, the opposite end seeks the sub-AC of coupling (correspondence) according to AC-id, have only when a sub-AC of Business Stream centering both-end all be that UP and PW are also during UP, just issue the hardware forwarding table item, transmit service message, otherwise do not transmit service message.Concrete grammar is as follows:

1, when the N TO 1 mode PW bind command of configuration AC, increase the configuration item of AC-id, it is right to be used to identify concrete sub-AC business.As shown in Figure 6, for example, for the subAC1-subAC3 business equals 1 to distributing an AC-id, for the subAC2-subAC4 business equals 2 to distributing an AC-id.

2, in the Notification message that sends, increase AC-id field and corresponding forwarding index, by AC-id, the state of the specific sub-AC of announcement opposite end PE local terminal.。

Referring to Fig. 6, Fig. 7, when the state of the first strip AC (supposition is subAC1) among all sub-AC of PW one end (as the PE1 end) became UP by DOWN, then PE1 sent the NotificationUP message, carries AC-id and the corresponding forwarding index of sub-AC in the message.After opposite end PE2 receives Notification UP message, seek the sub-AC business (subAC3) of coupling, if PE2 terminal AC (subAC3) service condition is DOWN, state to terminal AC (subAC1) in the PE2 data structure is changed to UP, if PE2 terminal AC (subAC3) service condition also is UP, and the state UP of PW then is changed to the state to terminal AC (subAC1) in the PE2 data structure UP and issues the hardware forwarding table item, begins to transmit service message; If the state DOWN of PW falls, then only the state to terminal AC (subAC1) in the PE2 data structure is changed to UP.When the state of last strip AC (supposition is subAC1) among all sub-AC of PW one end (as the PE1 end) becomes DOWN by UP, then send Notification DOWN message, carry the AC-id of sub-AC in the message.After opposite end PE2 receives Notification DOWN message, seek the sub-AC business (subAC3) of coupling, if PE2 terminal AC (subAC3) service condition is UP, the state UP of PW, then the state to terminal AC (subAC1) in the PE2 data structure is changed to DOWN and deletes the hardware forwarding table item, otherwise only the state to terminal AC (subAC1) in the PE2 data structure is changed to DOWN.Like this, PE also can clearly know PW state, this terminal of Business Stream centering AC state and to terminal AC state.

Among the present invention, the state of the state of PW and sub-AC business is carried out strict differentiation.If the mark of agreement PE two ends PW all distributes (both sent out mark Mapping message to the opposite end, and also received the mark Mapping message from the opposite end), then the state of PW is exactly UP, otherwise the state of PW is exactly DOWN.Do like this, make the state of PW be independent of the AC state, the differentiation of state is clearer and more definite, to the understanding of agreement and implement more clear, simultaneously also more in the protocol compliant " (draft-ietf-pwe3-control-protocol-14.txt " among the PWE3Reference Model of regulation to the understanding of PW, that is to say that the state of PW should be independent with the AC state.

3, adjust the PW message frame encapsulation format of N TO 1 mode

Referring to Fig. 8, with the PW message frame encapsulation format of N TO 1 mode of ATM be adjusted into the example explanation our for the adjustment scheme of N TO 1 mode PW encapsulated message form.Remove VPI, vci field in the N TO 1 ATM PW message frame encapsulation format, use concrete PVC of index of forwarding index field of AC-id correspondence instead.Receive that the forwarding index according to the AC-id correspondence removes to search corresponding PVC after the N TO 1 ATM PW message frame, so not only can make to search to reach linear speed, and can reduce hard-wired complexity.For the adjustment of N TO 1 encapsulation format of other pseudo-line services in like manner, as the artificial service of FR, the forwarding index field of also using the AC-id correspondence instead comes concrete FR Business Stream of index.

From as can be seen above, the present invention is by introducing the mechanism of subservice number, and it is right to make PE equipment can distinguish concrete AC business, and the PW state UP that the right AC UP that can not produce non-business causes, but the situation that E-Packets that can not be real.And, can also avoid the not high problem of PVC efficient by inputvpi/inputvci hardware searching correspondence by this mechanism.

Be understandable that, for those of ordinary skills, can be equal to replacement or change according to technical scheme of the present invention and inventive concept thereof, and all these changes or replacement all should belong to the protection range of the appended claim of the present invention.

Claims

1, a kind of method for recognizing multiple emulation service flow path, described method comprises:

2, method according to claim 1 is characterized in that, the described message of informing comprises: inform normal message and inform improper message.

3, method according to claim 2 is characterized in that, described step B specifically comprises:

4, method according to claim 3 is characterized in that, described step C specifically comprises:

5, method according to claim 4 is characterized in that, described step D specifically comprises:

6, method according to claim 4 is characterized in that, described step D also comprises:

7, method according to claim 2 is characterized in that, when the state of last sub-accessory circuit of pseudo-line first end became abnormal operating state by normal operating conditions, this end first service provider's equipment sends informed improper message; Describedly inform that improper message carries the identifier of sub-accessory circuit.

8, method according to claim 7 is characterized in that, described step C also comprises step:

9, method according to claim 8 is characterized in that, described step D specifically comprises:

10, method according to claim 2, it is characterized in that, adjust the pseudo-line encapsulated message form of many public simulated line modes of Business Stream, forwarding index field with accessory circuit identifier correspondence replaces identifier of the virtual route/virtual channel identifier field, and permanent virtual of index sign connects.

11, according to any described method of claim 1 to 10, it is characterized in that: described method also comprises:

Judge whether pseudo-line vpn label distributes;

If the described label of the pseudo-line in service provider equipment two ends all distributes, then the state of pseudo-line is exactly a normal operating conditions, otherwise,

The state of pseudo-line is exactly an abnormal operating state.