CN102710519A

CN102710519A - Method, system and device for establishing and removing cross-domain LSP (Label Switching Path)

Info

Publication number: CN102710519A
Application number: CN2012101789025A
Authority: CN
Inventors: 祝沈财; 段方红
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2012-06-01
Filing date: 2012-06-01
Publication date: 2012-10-03

Abstract

The invention discloses a method for establishing a cross-domain LSP (Label Switching Path). The method comprises the following steps: after a target address corresponding to a forwarding equivalence class FEC is obtained by a label edge router (LER), if a longest matching route of the target address is searched locally, transmitting label REQUEST information of FEC to a next hop of label switching router (LSR) corresponding to the longest matching route; after the label request REQUEST information of FEC is received by LSR, if a longest matching route of the target address of the FEC is searched locally, transmitting label REQUEST information of FEC to a next hop of LSR corresponding to the longest matching rout or transmitting label MAPPING information of FEC to LER or LSR for transmitting the label REQUEST information of FEC. The invention further discloses a system and a device for establishing the cross-domain LSP, and a method, a system and a device for removing the cross-domain LSP, by adopting the invention, the problem of incapability of establishing or removing the cross-domain LSP under a DOD (Downstream On Demand) label distribution mode by the conventional seamless MPLS (Multi-Protocol Label Switching) network end-to-end device.

Description

A kind of method, system and equipment of setting up and removing cross-domain LSP

Technical field

The present invention relates to seamless multiprotocol label switching (mpls) technical field, relate in particular to a kind of method, system and equipment of setting up and removing cross-domain label switched path (LSP) in the seamless MPLS network.

Background technology

Seamless (Seamless) multiprotocol label switching (MPLS; Multi-Protocol Label Switching) technology can guarantee in network access layer, convergence-level and core layer, to provide unified control plane; It can ensure the fast detecting of fault; And have characteristics such as network convergence, redundancy protecting, load balancing, satisfied the demand of home business, mobile retransmission (backhaul) and commercial occupation.

Virtual network operator and service provider can provide miscellaneous service by any convenience point flexibly in network; With seamless MPLS technology at VPN (VPN; Virtual Private Network) be applied as example in, as shown in Figure 1, pseudo-line (PW; Pseudo Wires) through network edge router between point-to-point connection; Access Network (AN, Access Network) and the WLAN (hereinafter to be referred as AGN) of supporting AGN (wireless protocols 802.11B/G/N) are coupled together and home business is provided, be connected through PW between AN and territory, the opposite end AN and commercial occupation is provided; Realize the seamless fusion of AN and core MPLS network, meet the trend that current communication service requirement is merged.

MPLS is the technology that is used for Fast IP packet switching and route, and the propagation delay time that it divides into groups IP shortens, and increases the speed of Network Transmission, is more suitable for the transmission of multimedia messages.The MPLS technology is stamped label (Label) for the IP grouping that gets into the MPLS network, and then the method through the label exchange realizes the forwarding that IP divides into groups, and label will have been given full play to the technical advantage of two layers of exchange and three layers of route as the substitute existence of IP packet header.

In the MPLS network; The fringe node of network is called tag edge router (LER; Label Edge Router); Wherein, IP is grouped in the LER that arrives when getting into the MPLS network and is called inlet (Ingress) LSR again, and IP is grouped in the LER that is arrived when leaving the MPLS network and is called outlet (Egress) LSR again.Inlet LSR divides into groups according to its different service grade and destination address distributing labels to the IP that gets into network, to be different forwarding equivalence class (FEC, Forwarding Equivalence Class) with the IP grouping and classifying, is labeled packet with the IP packet encapsulation simultaneously; The server node is called LSR (LSR; Label Switching Router); Claim inner LSR again, inner LSR carries out the forwarding that FEC was consulted and supported to label through tag distribution protocol (LDP, Label Distribution Protocol) and other nodes; Egress LSR is untied encapsulation to the labeled packet of deviated from network and is reduced to IP and divides into groups to go forward side by side walking along the street by forwarding.IP divides into groups to be called label forwarding path (LSP, Label Switching Path) from arriving inlet LSR to leaving the path of egress LSR in transmission through network, wherein, the coming of IP transmitted in packets to being called the upper reaches, whereabouts is called downstream.

The forming process of LSP is also relevant with the label distribution pattern, and at present, label distribution pattern commonly used is divided into: Downstream on Demand (Downstream On Demand, DOD) autonomous (Downstream Unsolicited, DU) distribution mode of distribution mode and downstream.Wherein, under the DOD pattern, only after receiving label request (REQUEST) message that send at the upper reaches, just the label of LSR distribution upstream shines upon (MAPPING) message to LSR; Under the DU pattern, LSR will initiatively be distributed to upper reaches LSR to label MAPPING message.

Edge LSR and inner LSR comprise routing module and distribution module on control plane; Distribution module generates the FEC clauses and subclauses according to the routing iinformation that routing module provides; And be that each FEC binds a label; Through LDP session (Session) and in abutting connection with LSR negotiating tags binding information, LSR gives upper reaches LSR with this binding information through label MAPPING message announcement after accomplishing the FEC label binding then; When each LSR except that inlet LSR on the LSP has all upstream announced label MAPPING information; And after each LSR except that egress LSR has received the corresponding label MAPPING message of sending in downstream; Inlet LSR will generate corresponding forwarding information base (FIB, Forwarding Information Base) list item; And the LSR on the LSP except that egress LSR will generate corresponding tag forwarding information base (LFIB, Label Forwarding Information Base) list item, thereby form the LSP of inlet LSR to egress LSR.

Along with the continuous expansion of MPLS network, for the ease of managing and reducing network overhead, network internal is divided into several autonomous territory (AS usually; Autonomous System; Hereinafter to be referred as the territory), the inner Interior Gateway Protocol (IGP, Interior Gateway Protocol) of carrying out in territory.Current; Because AN quantity in network is very big; In order to reduce the load of IGP in the network, can open the route aggregation function usually, like this; Can cause the only announcement in (ISIS LEVEL1) between the route of its input field of loopback (loopback) address of AN, and the route of (ISIS LAVEL2) is only announced the polymerization route between territory, opposite end and territory; Simultaneously, AN does not require and supports IGP, and only support static routing that this just makes local AN can not obtain the accurate routing iinformation of far-end AN, can't set up cross-domain LSP in order to reduce complexity and to build maintenance cost.

As shown in Figure 2, provider edge router (PE, Provider Edge Router) PE2, PE3 be last to have loopback address 10.1.1.1/32 and 10.1.1.2/32 respectively; Domain border router (ABR, Area Border Router) ABR2 is given in announcement, and ABR2 is only to other territory announcement polymerization routes 10.1.1.0/24; Therefore; ABR1 and PE1 only learn polymerization route 10.1.1.0/24, and dotted line is represented the advertising of route flow process among Fig. 2, like this; Just cause PE1 can't obtain the accurate routing iinformation of PE2 and PE3, can't set up cross-domain LSP from PE1 to remote domain PE2 and PE3.

For head it off; Longest path has been proposed by the coupling flow process among the RFC5283; This flow process is defaulted as closed condition and need opens through configuration, and this flow process is: LSR receives the label MAPPING message of the FEC that downstream LSR sends, if can inquire the longest coupling route of this FEC destination address in this locality; And corresponding next jumping of this route is for sending the LSR of this label MAPPING message; Then these upper reaches LSR will be used for the forwarding of this FEC, be this FEC distributing labels, upstream announce the label MAPPING message of this FEC simultaneously.

Concrete, it is as shown in Figure 2 that matched routings and LSP set up flow process, and PE2 is FEC (10.1.1.1/32) distributing labels value 3; To the label MAPPING message of ABR2 announcement FEC (10.1.1.1/32), ABR2 receives the label MAPPING message of FEC (10.1.1.1/32), is FEC (10.1.1.1/32) distributing labels value 16; The label MAPPING message of FEC (10.1.1.1/32) is announced at the upper reaches simultaneously; ABR1 arrive the longest coupling route 10.1.1.0/24 at local search, and ABR2 is next jumping of corresponding 10.1.1.0/24 according to the label MAPPING message that receives; Then ABR1 will be used to transmit FEC (10.1.1.1/32); Be FEC (10.1.1.0/24) distributing labels value 17, upstream announce the label MAPPING message of FEC (10.1.1.1/32) simultaneously, Fig. 2 solid line is represented above-mentioned label distribution process.Like this; All upstream announced the label MAPPING message of FEC (10.1.1.1/32) from the ABR1 node to the PE2 node; Generated corresponding forwarding-table item; Set up the cross-domain LSP of PE1--＞ABR1--＞ABR2--＞PE2 through above-mentioned flow process, above-mentioned flow process is equally applicable to the foundation of PE1--＞ABR1--＞cross-domain LSP of ABR2--＞PE3.

In the method for building up of above-mentioned cross-domain LSP, label distribution adopts the DU pattern end to end, because AN quantity is very big in the existing network, causes the formed FEC in loopback address of all AN to converge inundation in the territory of living in, can't alleviate the load of converging LDP in the territory.Begin to adopt the DOD mode to carry out label distribution if converge the territory from the AN node, as shown in Figure 3, on AN, trigger the LDP session through the PW business configuration; Create the FEC that points to loopback address, territory, opposite end; And to its direct-connected AGN request label, AGN equipment is signed REQUEST message according to route to the issue of bidding documents of effective downstream, like this; Can guarantee that the LSP that only sets up to request creates FEC; FEC also only creates in the AGN equipment on LSP simultaneously, alleviates the load of AN and AGN greatly, has solved the problem that exists under the DU label distribution pattern.

But; The method of setting up cross-domain LSP that RFC5283 describes only limits under the DU pattern; Under the DOD pattern; If the loopback address at AN does not only support under the situation of IGP in announcement of territory, place and AN that because label MAPPING message can not initiatively upstream be announced in downstream, the flow process that causes using RFC5283 to describe is set up cross-domain LSP.As shown in Figure 3, PE2, PE3 be last to have loopback address 10.1.1.1/32 and 10.1.1.2/32 respectively, and ABR2 is given in announcement; And ABR2 is only to other territory announcement polymerization routes 10.1.1.0/24; And AN does not support IGP, then between PE1 and the ABR1, can't exchanging routing information between PE2 and the ABR2, between PE3 and the ABR3, and therefore; ABR1 and PE1 can only learn polymerization route 10.1.1.0/24, and the advertising of route flow process is shown in dotted line among Fig. 3.

Because the label distribution between PE1 and the ABR1, between ABR1 and the ABR2 adopts the DOD pattern; ABR2 can not initiatively upstream announce the label MAPPING message of FEC (10.1.1.1/32); Can't implement the method for RFC5283 description and set up cross-domain LSP, cause to realize building of seamless MPLS network.

It is thus clear that in the existing seamless MPLS network, AN adopts the DU pattern to the label distribution of AGN end, under this pattern, the load of converging LDP in the territory is very heavy, has increased the cost that networking is safeguarded.If label distribution adopts the DOD pattern end to end; Though can solve the very heavy problem of LDP load in the territory that converges, AN can only support static routing in order to reduce complexity and to build maintenance cost, and when opening the polymerization routing function for the load that reduces IGP in the MPLS network; Can not set up cross-domain LSP; Can't realize the seamless fusion of AN and MPLS network, Virtual network operator and service provider can't provide miscellaneous service by convenience point flexibly in network, influenced user experience.

Summary of the invention

In view of this, the present invention provides a kind of method, system and equipment of setting up and removing cross-domain LSP, makes end-to-end equipment under DOD label distribution pattern, can set up or remove cross-domain LSP, reaches the purpose of building seamless MPLS network.

For achieving the above object, technical scheme of the present invention is achieved in that

The invention discloses the method for a kind of LSP of foundation, this method comprises:

After LER obtains the destination address corresponding with FEC,, then jump the label REQUEST message that LSR sends FEC to corresponding next of the longest said coupling route if in the longest coupling route of local search to said destination address;

After LSR receives the label REQUEST message of FEC; If in the long coupling route of local search, then jump LSR and send the label REQUEST message of FEC or the label MAPPING message of sending FEC to the LER that sends label REQUEST message or LSR to corresponding next of the longest said coupling route to said FEC destination address.

In the such scheme, saidly jump LSR to corresponding next of the longest said coupling route and send the label REQUEST message of FEC or be to the label mapping MAPPING message that the LER that sends label REQUEST message or LSR send FEC:

LSR judges whether to receive the label MAPPING message that corresponding next of the longest coupling route jumped the FEC that LSR sends, if, the label mapping MAPPING message of then sending FEC to the LER that sends label REQUEST message or LSR; Otherwise, jump the label REQUEST message that LSR sends FEC to corresponding next of the longest said coupling route.

In the such scheme, said LSR comprises to the label MAPPING message of LER that sends label REQUEST message or LSR transmission FEC:

Said LSR is the FEC distributing labels, and the binding information of said FEC and label is carried at LER or the LSR that sends to the said FEC label REQUEST message of transmission in the label MAPPING message.

The invention also discloses a kind of method of removing cross-domain LSP, this method comprises:

LSR receives the label RELEASE message of FEC, be checked through local FEC and be cross-domain formation the time, announce label RELEASE message downstream.

The invention also discloses a kind of LER, this equipment comprises: destination address acquiring unit, the first via are by query unit, first message sending unit; Wherein,

Said destination address acquiring unit is used to obtain the destination address corresponding with FEC;

The said first via is used for after the destination address acquiring unit obtains the destination address corresponding with FEC by query unit, in the longest coupling route of the said destination address of local search;

Said first message sending unit is used for the first via is inquired the longest coupling route of said destination address by query unit after, jumps the label REQUEST message that LSR sends FEC to corresponding next of the longest said coupling route.

The invention also discloses a kind of LSR, this equipment comprises: the first message sink unit, secondary route query unit, second message sending unit; Wherein,

The said first message sink unit is used to receive the label REQUEST message of FEC;

Said secondary route query unit is used for after the label REQUEST message of FEC is received in the first message sink unit, in the longest coupling route of the said FEC destination address of local search;

Said second message sending unit; Be used for when the secondary route query unit inquires the longest coupling route of FEC destination address, jumping LSR to corresponding next of the longest said coupling route and sending the label REQUEST message of FEC or the label MAPPING message of sending this FEC to the LER or the LSR of the label REQUEST message of sending FEC.

In the such scheme, said LSR also comprises: judging unit, corresponding next of the longest coupling route of the FEC destination address that is used to judge whether to receive that the secondary route query unit inquires are jumped the label MAPPING message of the FEC that LSR sends;

In the such scheme, said second message sending unit specifically is used in the judgment unit judges result when being, the label MAPPING message of sending this FEC to the LER or the LSR of the label REQUEST message of sending FEC; For not the time, jump the label REQUEST message that LSR sends FEC in the judgment unit judges result to corresponding next of the longest said coupling route.

In the such scheme, said second message sending unit comprises:

The label distribution subelement is used for receiving in the first message sink unit label REQUEST message of FEC, and the secondary route query unit is said FEC distributing labels when inquiring the longest coupling route of address of said FEC;

Message is sent subelement, and being used for the label distribution subelement is the binding information of said FEC distributed labels and FEC, is carried at the LER or the LSR that send to the label REQUEST message of sending said FEC in the label MAPPING message.

The invention also discloses a kind of system that sets up cross-domain LSP, this system comprises above-mentioned LER and above-mentioned LSR more than; Wherein,

Said LER after being used to obtain the destination address corresponding with FEC, if in the longest coupling route of local search to said destination address, then jumps the label request REQUEST message that LSR sends FEC to corresponding next of the longest said coupling route;

Said LSR; After being used to receive the label REQUEST message of FEC; If in the longest coupling route of local search, then jump LSR and send the label REQUEST message of FEC or the label MAPPING message of sending this FEC to the LER or the LSR of the label REQUEST message of sending FEC to corresponding next of the longest said coupling route to said FEC destination address.

The invention also discloses a kind of LSR, this equipment comprises: the second message sink unit, cross-domain detecting unit, the 3rd message sending unit; Wherein,

The said second message sink unit is used to receive the label RELEASE message of FEC;

Said cross-domain detecting unit is used for after the label RELEASE message of FEC is received in the second message sink unit, detects whether cross-domain formation of said FEC;

Said the 3rd message sending unit is used in cross-domain detection announcing label RELEASE message downstream when said FEC is cross-domain formation.

The invention also discloses a kind of system of removing cross-domain LSP, this system comprises above-mentioned LSR: wherein,

Said LSR is used to receive the label RELEASE message of FEC, be checked through local FEC be cross-domain formation the time, announce label RELEASE message downstream.

In the technical scheme provided by the present invention, after LER obtains the destination address corresponding with FEC,, then jump the label REQUEST message that LSR sends FEC to corresponding next of this longest coupling route if in the longest coupling route of local search to this destination address; After LSR receives the label REQUEST message of FEC; If in the longest coupling route of local search, then send the label MAPPING message of FEC or jump the label REQUEST message that LSR sends FEC to corresponding next of this longest coupling route to this LSR that sends label REQUEST message to this FEC destination address.It is thus clear that; The present invention is at complexity that reduces AN and construction maintenance cost; When alleviating the IGP load of MPLS network, can make end to end equipment under DOD label distribution pattern, set up cross-domain LSP, realize building of seamless MPLS network; And then make Virtual network operator and service provider in network, miscellaneous service is provided any convenience point flexibly, improved user experience.Accordingly, the present invention can also make end-to-end equipment under DOD label distribution pattern, remove cross-domain LSP.

Description of drawings

Fig. 1 is a seamless MPLS application scenarios sketch map in the prior art;

Fig. 2 sets up cross-domain LSP scene sketch map for what RFC5283 was suitable for;

Fig. 3 can't set up the scene sketch map of cross-domain LSP for RFC5283;

Fig. 4 sets up and removes the realization flow sketch map of cross-domain LSP method for the present invention;

The realization flow sketch map of Fig. 5 cross-domain LSP method for the present invention removes;

Fig. 6 sets up the realization flow sketch map of cross-domain LSP for the present invention;

Fig. 7 removes the realization flow sketch map of cross-domain LSP for the present invention.

Embodiment

It is as shown in Figure 4 that the present invention sets up the method realization flow of cross-domain LSP, and this method comprises:

Step 401:LER obtains the destination address corresponding with FEC;

Step 402: if LER in the longest coupling route of local search to this destination address, then jumps the label REQUEST message that LSR sends FEC to corresponding next of this longest coupling route;

If LER in the accurate coupling route of local search to this FEC destination address, then carried out the operation of setting up LSP according to the rules of RFC5036 before the longest coupling route of this destination address of local search.

Whether LER can allow for FEC according to the local configuration of rules inspection of RFC5283 and do longest path by coupling before the longest coupling route of this FEC destination address of local search.

LER waits for the label MAPPING message that next corresponding jumping LSR of this longest coupling route sends according to the rules of RFC5036 after corresponding next of this longest coupling route jumped the label request REQUEST message of this FEC of LSR LSR transmission.

If LER can not inquire the accurate coupling route of the destination address of this FEC, can not inquire the longest coupling route of this FEC destination address, then finish this operation.

Wherein, the longest coupling route of this FEC destination address of said inquiry is meant, and is the most approaching at local search and this FEC destination address mask-length, and in the prefix of the identical mask-length also route of unanimity.

For example; This locality exists route 10.1.1.0/24,10.1.0.0/16 and 10.1.2.0/24; The destination address of FEC is 10.1.1.2/32, and the destination address mask-length of this FEC is 32, and the mask-length of route 10.1.1.0/24,10.1.0.0/16 and 10.1.2.0/24 is respectively 24,16 and 24; Wherein, The destination address mask-length 32 of the mask-length of route 10.1.1.0/24 and 10.1.2.0/24 and FEC is the most approaching; And in this mask-length; Route 10.1.1.0/24 is consistent with the destination address 10.1.1.2/32 prefix of this FEC, and therefore, the longest coupling route that inquires FEC destination address 10.1.1.2/32 is 10.1.1.0/24.

Wherein, The accurate coupling route of this FEC destination address of said inquiry is meant, in local search and this FEC destination address prefix and the consistent route of mask-length, for example; The destination address of FEC is 10.1.1.1/32, and then corresponding with the destination address of this FEC accurate coupling route is 10.1.1.1/32.

Step 403:LSR receives the label REQUEST message of FEC;

Step 404: if LSR in the longest coupling route of local search to this FEC destination address, then jumps LSR to corresponding next of this longest coupling route and sends the label REQUEST message of FEC or the label MAPPING message of sending this FEC to the LER or the LSR of the label REQUEST message of sending FEC;

If LSR in the accurate coupling route of local search to this FEC destination address, then carried out the operation of setting up LSP according to the rules of RFC5036 before the longest coupling route of this FEC destination address of local search.

LSR arrives at local search before the longest coupling route of this FEC destination address, can whether allow for FEC according to RFC5283 rules inspection this locality configuration and do longest path by coupling.

LSR waits for the label MAPPING message that next corresponding jumping LSR of this longest coupling route sends according to the rules of RFC5036 after corresponding next of this longest coupling route jumped the label request REQUEST message of this FEC of LSR LSR transmission.

If LSR had not both inquired accurate coupling route in this locality, do not inquire the longest coupling route yet, then, send NOROUTE message to LER that sends label REQUEST message or LSR according to the rules of RFC5036.

Wherein, Said LSR jumps label MAPPING message that LSR sends the label REQUEST message of FEC or send this FEC to the LER or the LSR of the label REQUEST message of sending FEC to corresponding next of this longest coupling route and is specially: LSR judges whether to receive the label MAPPING message that corresponding next of the longest coupling route jumped the FEC that LSR sends; If, then to the label mapping MAPPING of LER that sends label REQUEST message or LSR transmission FEC message; Otherwise, directly jump the label REQUEST message that LSR sends FEC to corresponding next of this longest coupling route.It is as shown in Figure 5 that the present invention removes the method realization flow of cross-domain LSP, and this method comprises:

Step 501:LSR receives the label RELEASE message of FEC;

Step 502:, then announce label RELEASE message downstream if being checked through local FEC is cross-domain formation; Trigger route deletion flow process simultaneously, carry out following operations by the rules of RFC5036: the deletion forwarding-table item, it is no routing state that FEC is set, ageing time is deletion FEC. to the back

After LSR receives the label RELEASE message of this FEC, not cross-domain formation, operate according to the rules of RFC5036 if be checked through local FEC.

Below in conjunction with specific embodiment the present invention is remake further detailed explanation.

Present embodiment is an example with networking situation shown in Figure 6; Present embodiment is applied in the seamless MPLS network; Equipment is set up the process of cross-domain LSP under DOD label distribution pattern end to end; All devices is in order to create cross-domain LSP in the network, and according to the rules of RFC5283, configuration allows to do longest path by coupling.In order to reduce the load of IGP in the network; The loopback address of AN is only in its territory, place announcement; Only announce the polymerization route between territory, opposite end and the territory, cause having only ABR2 to acquire route 10.1.1.1/32 and 10.1.1.2/32, PE1 and ABR1 can't acquire route 10.1.1.1/32 and 10.1.1.2/32; Only acquire polymerization route 10.1.1.0/24, the advertising of route process is shown in dotted line among Fig. 6.

The triggering of setting up flow process of cross-domain LSP comprises several kinds of situation:

(1) static PW triggers cross-domain LSP foundation:

As shown in Figure 6, PE1 is last to dispose a PW opposite end address 10.1.1.1/32, is configured to PE1 and triggers and create the corresponding FEC (10.1.1.1/32) of public network LSP.

(2) the cross-domain LSP of static configuration LSP configure trigger sets up:

As shown in Figure 6, the foundation of cross-domain LSP also can trigger through the LSP static configuration.On the PE1 node, static Label In or the Label Out of LDP configuration FEC (10.1.1.1/32) create FEC (10.1.1.1/32).

Cross-domain LSP sets up flow process:

PE1 is according to the accurate coupling route of the rules inquiry 10.1.1.1/32 of RFC5036; Because PE1 only acquires polymerization route 10.1.1.0/24; Therefore can't inquire the accurate coupling route of 10.1.1.1/32 in this locality; Simultaneously whether allow for FEC according to the local configuration of rules inspection of RFC5283 and do longest path by coupling, because local configuration allowed to do longest path by coupling, operation: PE1 below then carrying out is in the longest coupling route of self inquiry 10.1.1.1/32; And to inquire the longest coupling route be 10.1.1.0/24; And it is ABR1 that corresponding next of this route jumped LSR, the PE1 label REQUEST message of sending FEC (10.1.1.1/32) then to ABR1, and wait for the label MAPPING message that ABR1 sends according to the rules of RFC5036;

After ABR1 receives the label REQUEST message of the FEC (10.1.1.1/32) that upstream PE 1 is sent; Rules according to RFC3215 are created upper reaches controll blocks (Upstream LSP Control Block), in this upper reaches controll block, preserve the record of receiving the label REQUEST message that upstream PE 1 is sent; Rules according to RFC5036 are created FEC; Inquire about the accurate coupling route of 10.1.1.1/32 according to the rules of RFC5036; Because ABR1 only acquires polymerization route 10.1.1.0/24; Therefore can't inquire the accurate coupling route of 10.1.1.1/32 in this locality, check according to the rules of RFC5283 whether local configuration allows for FEC and do longest path by coupling simultaneously, because local the configuration allowed to do longest path by coupling; Operation: ABR1 below then carrying out self is inquiring about the longest coupling route of 10.1.1.1/32; And to inquire the longest coupling route be 10.1.1.0/24, and corresponding next of this route to jump LSR be ABR2 owing to do not receive the label MAPPING message of the FEC (10.1.1.1/32) that ABR2 sends; Therefore the ABR1 label REQUEST message of sending FEC (10.1.1.1/32) to ABR2, and wait for the label MAPPING message that ABR2 sends according to the rules of RFC5036;

ABR2 receives before the label REQUEST message of the FEC (10.1.1.1/32) that ABR1 sends; Learnt route 10.1.1.1/32; Then ABR2 and PE2 carry out following operations: ABR2 according to the rules of RFC5036 and send FEC (10.1.1.1/32) label REQUEST message to PE2, are FEC (10.1.1.1/32) distributing labels value 16; After PE2 receives the label REQUEST message of the FEC (10.1.1.1/32) that ABR2 sends, be FEC (10.1.1.1/32) distributing labels value 3, and the binding information of this label value and FEC (10.1.1.1/32) is carried at label MAPPING message sends to ABR2; After ABR2 receives the label MAPING message of the FEC (10.1.1.1/32) that PE2 sends, generate forwarding-table item;

After ABR2 receives the label REQUEST message of the FEC (10.1.1.1/32) that ABR1 sends, press the rules of RFC3215 and create upper reaches controll block, in this upper reaches controll block, preserve the record of receiving the label REQUEST message that ABR1 sends.Because ABR2 has acquired accurate coupling route 10.1.1.1/32, therefore operate according to the rules of RFC5036: ABR2 sends FEC (10.1.1.1/32) label MAPPING message to ABR1;

After ABR1 receives the label MAPPING message of the FEC (10.1.1.1/32) that ABR2 sends; Be FEC (10.1.1.1/32) distributing labels value 17; And the binding information of this label value and FEC (10.1.1.1/32) is carried at label MAPPING message sends to PE1, the rules according to RFC5036 generate forwarding-table item simultaneously;

After PE1 receives the label MAPPING message of the FEC (10.1.1.1/32) that ABR1 sends,, generate forwarding-table item according to the rules of RFC5036.

Through above-mentioned flow process; LSP from the PE1 node to the PE2 node each LSR except that PE1 has all upstream announced the label MAPPING information of FEC (10.1.1.1/32); And each LSR except that PE2 has received the corresponding label MAPPING message that send in downstream; Set up the cross-domain LSP of PE1--＞ABR1--＞ABR2--＞PE2 through above-mentioned flow process, can set up the cross-domain LSP of PE1--＞ABR1--＞ABR2--＞PE3 equally through above-mentioned flow process.

Wherein, PE1/ABR1 two nodes are respectively by configuration and the longest coupling flow process of label REQUEST message trigger, for FEC sets up cross-domain LSP; ABR2/PE2 two nodes are still triggered by accurate coupling route, for FEC sets up LSP.Set up in the process at cross-domain LSP, label REQUEST message and label MAPPING message transmission flow are shown in solid line among Fig. 6.

Fig. 7 has provided with Fig. 6 and has set up the corresponding cross-domain LSP dismounting flow process of cross-domain LSP, comprising:

On the PE1 node; Through order deletion address, opposite end is the PW configuration of 10.1.1.1/32 or the static labels configuration of deletion FEC (10.1.1.1/32); PE1 can't inquire the accurate coupling route of 10.1.1.1/32 according to the rules of RFC5036; Because local configuration has allowed to do longest path by coupling,, therefore be checked through local FEC (10.1.1.1/32) and be cross-domain formation then in the longest coupling route of self inquiry and inquire the longest coupling route 10.1.1.0/24; PE1 removes the operation of cross-domain LSP: ABR1 announces the label RELEASE message of FEC (10.1.1.1/32) downstream; And carry out following operations according to the rules of RFC5036: the forwarding-table item that deletion FEC (10.1.1.1/32) is corresponding, it be no routing state that FEC (10.1.1.1/32) is set, FEC (10.1.1.1/32) will ageing time to after delete;

After ABR1 receives the label RELEASE message of FEC (10.1.1.1/32); Rules deletion upper reaches controll block according to RFC3215; Can't inquire the accurate coupling route of 10.1.1.1/32 simultaneously according to the rules of RFC5036; Because local configuration has allowed to do longest path by coupling,, therefore be checked through local FEC (10.1.1.1/32) and be cross-domain formation then in the longest coupling route of self inquiry and inquire the longest coupling route 10.1.1.0/24; ABR1 carries out the operation of the cross-domain LSP of following dismounting: the label RELEASE message of announcing FEC (10.1.1.1/32) downstream; And carry out following operations according to the rules of RFC5036: the forwarding-table item that deletion FEC (10.1.1.1/32) is corresponding, it be no routing state that FEC (10.1.1.1/32) is set, FEC (10.1.1.1/32) will ageing time to after delete.

ABR2 receives the label RELEASE message of FEC (10.1.1.1/32), to accurate coupling route 10.1.1.1/32, therefore is checked through local FEC (10.1.1.1/32) and is not cross-domain formation, according to the rules deletion upper reaches controll block of RFC3215 at local search.

Make the cross-domain LSP of PE1--＞ABR1--＞ABR2--＞PE2 by complete dismounting through above-mentioned flow process, can make the cross-domain LSP of PE1--＞ABR1--＞ABR2--＞PE3 by complete dismounting equally through above-mentioned flow process.

For realizing said method, the invention provides a kind of LER, comprising: destination address acquiring unit, the first via are by the query unit and first message sending unit; Wherein,

The present invention also provides a kind of LSR, comprises the first message sink unit, secondary route query unit, second message sending unit; Wherein,

This LSR also comprises: judging unit, corresponding next of the longest coupling route of the FEC destination address that is used to judge whether to receive that the secondary route query unit inquires are jumped the label MAPPING message of the FEC that LSR sends;

Said second message sending unit specifically is used in the judgment unit judges result sending the label MAPPING message of this FEC to the LSR of the label REQUEST message of sending FEC when being; For not the time, jump the label REQUEST message that LSR sends FEC in the judgment unit judges result to corresponding next of the longest said coupling route.

Said second message sending unit comprises: label distribution subelement and message are sent subelement; Wherein,

Message is sent subelement, and being used for the label distribution subelement is the binding information of said FEC distributed labels and FEC, is carried at the LSR that sends to the label REQUEST message of sending said FEC in the label MAPPING message.

Accordingly, the present invention also provides a kind of system that sets up cross-domain LSP, comprises LER and an above LSR; Wherein,

Said LER comprises: destination address acquiring unit, the first via be by the query unit and first message sending unit, the function of each unit with above said identical; Said LSR comprises the first message sink unit, secondary route query unit, second message sending unit; Further can also comprise judging unit; Said second message sending unit comprises that label distribution subelement and message sends subelement, the function of each unit with above said identical.

The present invention provides a kind of LSR again, comprising: the second message sink unit, cross-domain detecting unit and the 3rd message sending unit; Wherein,

Accordingly, the present invention also provides a kind of system of removing cross-domain LSP, comprises LSR, is used to receive the label RELEASE message of FEC, be checked through local FEC be cross-domain formation the time, announce label RELEASE message downstream.

Wherein, said LSR comprises: the second message sink unit, cross-domain detecting unit and the 3rd message sending unit, the function of each unit with above said identical.

More than explanation; Be merely the preferable practical implementation method of the present invention, but protection scope of the present invention is not limited thereto, any technical staff who is familiar with the present technique field is in the technical scope that the present invention discloses; The variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claims.

Claims

1. a method of setting up cross-domain label switching path LSP is characterized in that, this method comprises:

After label edges TSR LER obtains the destination address corresponding with forwarding equivalence class FEC; If in the longest coupling route of local search, then jump the label request REQUEST message that LSR LSR sends FEC to corresponding next of the longest said coupling route to said destination address;

After LSR receives the label REQUEST message of FEC; If in the long coupling route of local search, then jump LSR and send the label REQUEST message of FEC or label mapping MAPPING message of sending FEC to the LER that sends label REQUEST message or LSR to corresponding next of the longest said coupling route to said FEC destination address.

2. method according to claim 1; It is characterized in that said LSR jumps LSR to corresponding next of the longest said coupling route and sends the label REQUEST message of FEC or to the label mapping MAPPING message that the LER that sends label REQUEST message or LSR send FEC be:

3. method according to claim 1 and 2 is characterized in that, said LSR comprises to the label MAPPING message of LER that sends label REQUEST message or LSR transmission FEC:

4. method of removing cross-domain LSP is characterized in that this method comprises:

LSR receives the label RELEASE message of FEC, be checked through local FEC and be cross-domain formation the time, announce the label RELEASE message of FEC downstream.

5. a LER is characterized in that, this LER comprises that destination address acquiring unit, the first via are by the query unit and first message sending unit; Wherein,

6. a LSR is characterized in that, this LSR comprises the first message sink unit, secondary route query unit, second message sending unit; Wherein,

7. LSR according to claim 6; It is characterized in that; This LSR also comprises: judging unit, corresponding next of the longest coupling route of the FEC destination address that is used to judge whether to receive that the secondary route query unit inquires are jumped the label MAPPING message of the FEC that LSR sends;

Said second message sending unit specifically is used in the judgment unit judges result when being, the label MAPPING message of sending this FEC to the LER or the LSR of the label REQUEST message of sending FEC; For not the time, jump the label REQUEST message that LSR sends FEC in the judgment unit judges result to corresponding next of the longest said coupling route.

8. according to claim 6 or 7 described LSR, it is characterized in that said second message sending unit comprises:

9. a system that sets up cross-domain LSP is characterized in that, this system comprises LER and an above LSR; Wherein,

10. system according to claim 9 is characterized in that, said LER is the said LER of claim 5; Said LSR is each said LSR of claim 6 to 8.

11. a LSR is characterized in that, said LSR comprises the second message sink unit, cross-domain detecting unit and the 3rd message sending unit; Wherein,

Said the 3rd message sending unit is used in cross-domain detection announcing the label RELEASE message of FEC downstream when said FEC is cross-domain formation.

12. a system of removing cross-domain LSP is characterized in that this system comprises:

LSR is used to receive the label RELEASE message of FEC, be checked through local FEC be cross-domain formation the time, announce label RELEASE message downstream.

13. system according to claim 12 is characterized in that, said LSR is the said LSR of claim 11.