CN102624615B

CN102624615B - Forwarding method and forwarding device for multicast data messages based on multiple protocol label switching (MPLS)

Info

Publication number: CN102624615B
Application number: CN201210053902.2A
Authority: CN
Inventors: 陈锦军
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: New H3C Information Technologies Co Ltd
Priority date: 2012-03-02
Filing date: 2012-03-02
Publication date: 2014-11-12
Anticipated expiration: 2032-03-02
Also published as: CN102624615A

Abstract

The invention provides a forwarding method and a forwarding device for multicast data messages based on a multiple protocol label switching (MPLS). The method includes that specialized multicast labels are assigned to multicast forwarding equivalence class (FEC) of a multicast transmission path, the multicast labels are notified to all nodes of the multicast transmission path; when each of the multicast labels assigned to the multicast FEC are obtained by each of nodes in multicast transmission path, a multicast label forwarding table related to the multicast labels and corresponding to a multicast forwarding table of the multicast FEC is established; and the multicast data messages forwarding are performed according to the multicast label forwarding table. According to the forwarding method and the forwarding device for the multicast data messages based on MPLS, the forwarding efficiency of the multicast data messages can be improved.

Description

Multicast data packet forwarding method and apparatus based on MPLS

Technical field

The present invention relates to communication technical field, particularly a kind of multicast data packet forwarding method and apparatus based on MPLS (multiprotocol label switching).

Background technology

MPLS is a kind of technology of utilizing label vectoring information high speed, high efficiency of transmission in open communication network, can effectively improve the forward efficiency of unicast data message by application MPLS technology, but, but cannot realize high forward efficiency for multicast data message.

In prior art, the forwarding that realizes principle and unicast data message of the forwarding of the multicast data message based on MPLS to realize principle identical: one of upstream LSR distribution of downstream LSR (LSR) enters label, and the label of LSRBa downstream, upstream LSR distribution and corresponding outgoing interface are bound; In the time of multicast data forwarding message, carry out copying of message and Tag Packaging for each outgoing interface, the multicast data packet forwarding after encapsulation is gone out.

Referring to Fig. 1, Fig. 1 is the multicast application networking schematic diagram of prior art based on MPLS, comprises multicast source, multicast receivers 1, multicast receivers 2, multicast receivers 3, router R1, router R2, router R3, router R4; Wherein, R1, R2, R3, R4 are the multicast label switch router (LSR) of supporting multicast forwarding and label function of exchange.

In networking shown in Fig. 1, in order to realize multicast data packet forwarding, R3, R4 distribute into label L3, L4 to R2 respectively, and R2 will enter label L3 and outgoing interface P3 binds, and will enter label L4 and outgoing interface P4 binds; R2 distributes into label L2 to R1, and R1 will enter label L2 and outgoing interface P2 binds; Like this, when multicast data message enters after R1, R1 will enter label L2 and send to R2 from outgoing interface P2 in multicast data message encapsulation; R2 ejects L2 label in the multicast data message receiving, is forwarded to R3 after copying and be encapsulated into label L3, is forwarded to R4 after copying and be encapsulated into label L4; R3 and R4 eject the label in the multicast data message receiving respectively, and are forwarded to the program request person who connects separately.

In said process, in R2, there are multiple outgoing interfaces, need to carry out copying of message and Tag Packaging for each outgoing interface, this can cause the forward efficiency of multicast data message low, can not embody by the meaning of label forwarding multicast data message.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of multicast data packet forwarding method based on MPLS, the method can improve the forward efficiency of multicast data message.

In order to achieve the above object, the invention provides a kind of multicast data packet forwarding method based on MPLS, the method comprises:

Current multicast label switch router LSR is as the head node of multicast transfer path, the multicast label that the multicast FEC that to obtain main multicast label distributor that BootStrap Router BSR selects be multicast transfer path distributes; Determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, set up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmit, transmit multicast data forwarding message according to multicast label; Otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, set up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmit, transmit multicast data forwarding message according to multicast label;

Current multicast LSR, as forward node and/or the tail contact of multicast transfer path, receives after the multicast label notification packet of upstream neighbor multicast LSR, obtains the multicast label for described multicast FEC distribution of carrying in multicast label notification packet; Determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, upstream neighbours' multicast LSR sends multicast label confirmation message, and the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmit, transmit multicast data forwarding message according to multicast label; Otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, upstream neighbours' multicast LSR sends multicast label confirmation message, and the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmit, transmit multicast data forwarding message according to multicast label.

The present invention also provides a kind of multicast LSR, the head node that this multicast LSR is multicast group, and this multicast LSR comprises: label acquiring unit, label notification unit, table are set up unit, message repeating unit;

Described label acquiring unit, for obtaining the multicast label of the multicast FEC distribution that the main multicast label distributor of BootStrap Router BSR selection is multicast transfer path;

Described label notification unit, for obtaining at label acquiring unit after the multicast label that main multicast label distributor is described multicast FEC distribution, determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, set up unit to table and send the first notice, otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, set up unit to table and send the first notice;

Described table is set up unit, for receiving after the first notice of label notification unit, sets up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmits;

Described message repeating unit, for transmitting multicast data forwarding message according to described multicast label.

The present invention also provides another kind of multicast LSR, the forward node that this multicast LSR is multicast group and/or caudal knot point, and this multicast LSR comprises: label acquiring unit, label notification unit, table are set up unit, message repeating unit;

Described label acquiring unit, the multicast label of distributing for receiving the multicast label notification packet of upstream neighbor multicast LSR, obtain multicast FEC that the main multicast label distributor that carries in multicast label notification packet is multicast transfer path; After knowing for the four-way that receives label notification unit, upstream neighbours' multicast LSR sends multicast label confirmation message;

Described label notification unit, for being retrieved as at label acquiring unit after the multicast label of described multicast FEC distribution, determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, sending four-way to label acquiring unit knows, and set up unit to table and send five-way and know, otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, sending four-way to label acquiring unit knows, and set up unit to table and send five-way and know,

From technical scheme above, in the present invention, the head node of multicast transfer path obtains after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, and this multicast label is noticed to the each downstream neighbor multicast LSR to self; Each downstream neighbor multicast LSR of head node obtains after this multicast label, continue again to notice the each downstream neighbor multicast LSR to self, the like, until all multicast LSR between from head node to tail node all obtain this multicast label, the multicast label that is associated with this multicast label corresponding to multicast forward table that each multicast LSR sets up separately in this process transmitted, and transmits according to this multicast label the forwarding of carrying out multicast data message.The present invention, in the time that multicast LSR has multiple outgoing interface, need to not carry out message for each outgoing interface and copy and encapsulate, and therefore can improve the forward efficiency of multicast message.

Brief description of the drawings

Fig. 1 is the multicast application networking schematic diagram of prior art based on MPLS;

Fig. 2 is embodiment of the present invention multicast label assigning process figure;

Fig. 3 is embodiment of the present invention multicast label announcement process figure;

Fig. 4 is the schematic flow sheet of the method for forwarding multicast message of the embodiment of the present invention based on MPLS;

Fig. 5 is the structural representation of a kind of multicast LSR of the embodiment of the present invention;

Fig. 6 is the structural representation of the another kind of multicast LSR of the embodiment of the present invention.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearer, below in conjunction with the accompanying drawing embodiment that develops simultaneously, technical scheme of the present invention is elaborated.

For convenience of description, below by the multicast transfer path between from multicast source to multicast receivers, the multicast LSR of direct-connected multicast source is called head (Ingress) node, the multicast LSR of direct-connected multicast receivers is called tail (egress) node, and other multicast LSR is called forwarding (Transit) node.

Main thought of the present invention is: for the multicast FEC of multicast transfer path distributes a unique multicast label, this multicast label is noticed to all multicast LSR in multicast transfer path; Each multicast LSR in multicast transfer path obtains after the multicast label of distributing for multicast FEC, sets up the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC and transmits; Transmit the forwarding of carrying out multicast data message according to multicast label.Here, multicast FEC, taking multicast group information as mark, is also that multicast FEC and multicast group information have relation one to one; Or taking multicast group and information about multicast source as mark, be also that multicast FEC and multicast group and information about multicast source have relation one to one.

The present invention is applicable to Protocol Independent Multicast (PIM) sparse mode/source specific multicast (SM/SSM) and bidirectional protocol-independent multicast (BIdir PIM) application networking.

First multicast label and multicast label distributor are described:

Owing to need to the each multicast FEC in network being distributed to a unique multicast label, in the embodiment of the present invention, can preset a multicast label scope, all labels within the scope of this multicast label can only be used for distributing to multicast FEC, can not distributed and use by other tag distribution protocol again by the label within the scope of this multicast label of System Assurance.For example, can define multicast label range is 65536 to 86016, all can only be assigned to multicast FEC so from all values between 65536 and 86016.

Can a multicast label distributor be set in multicasting MPLS scope territory, carry out unified distribution and the recovery of the multicast label in network by multicast label distributor.Any one configuration of routers in network can be become to multicast label dispenser, for example, in Fig. 1, R1, R2, R3, R4 all can be configured to multicast label distributor, multicast label distributor that also can configure dedicated.Based on reliability consideration, can configure multiple multicast label distributors simultaneously, select one of them as main multicast label distributor, carried out distribution and the recovery of multicast label by main multicast label distributor, in the time of main multicast label distributor fault, reselect one as main multicast label distributor at other all not fault multicast label distributors.

Can configure an equipment, for example BootStrap Router (BSR) carries out the fault detect of multicast label distributor and the selection of main multicast label distributor.Each multicast label distributor can send multicast label distributor notification packet to BSR, in multicast label distributor notification packet, carry this multicast label distributor relevant information, the information such as address, priority of for example this multicast label distributor, thus inform that BSR is certainly as multicast label distributor.

BSR is receiving after the multicast label distributor notification packet of all multicast label distributors, can obtain and store the multicast label distributor relevant information of carrying in multicast label dispenser notification packet, and therefrom selects one as main multicast label distributor.

After having selected main multicast label distributor, BSR also needs the main multicast label distributor of this selection to be flooded in network.Here, BSR can become the BSR message of expansion to flood to the whole network in company with candidate's convergent point (RP) Information encapsulation main multicast label distributor relevant information, finally makes all multicast LSR in network obtain identical main label distributor relevant information and RP information.

BSR can detect whether fault of multicast label dispenser by multicast label distributor being carried out to burin-in process.Each multicast label distributor periodically (for example, every the first Preset Time) sends multicast label distributor notification packet to BSR; When BSR receives the multicast label distributor notification packet of this multicast label distributor first, can obtain and store the relevant information of this multicast label distributor carrying in multicast label dispenser notification packet, the first ageing time of this multicast label distributor can also be set simultaneously; Here, the first ageing time should be less than the first Preset Time, and this first ageing time can preset in BSR, also can in multicast label distributor, preset, and be carried in multicast label distributor notification packet and to notice to BSR.

In the normal situation of multicast label distributor, can send multicast label distributor notification packet every the first Preset Time, like this, BSR can again receive the multicast label distributor notification packet of this multicast label distributor in the first ageing time of this multicast label distributor, and refreshes the first ageing time of this multicast label distributor.In the situation of multicast label distributor fault, cannot continue to send multicast label distributor notification packet, therefore, BSR can be after the first ageing time of this multicast label distributor be overtime again, determine this multicast label distributor fault, by aging the relevant information of this multicast label distributor of storage.

BSR detects after certain multicast label distributor fault, need to judge whether this multicast label distributor is main multicast label distributor, if, also need in all multicast label distributors of fault not, reselect one as main multicast label distributor, and the new main multicast label router relevant information of this selection is flooded in network, make all multicast LSR in network obtain new main label distributor relevant information.

Secondly, multicast label distribution and recovery are described:

Multicast label is distributed and can be initiated by the head node of multicast transfer path.Head node can send to main multicast label distributor the multicast label request message of the multicast FEC information of carrying multicast transfer path, and described multicast FEC information can comprise multicast group, information about multicast source; Main multicast label distributor receives after the multicast label request message of head node, if be not yet that this multicast FEC distributes multicast label, can within the scope of multicast label, select at random a unappropriated multicast label, this multicast label is carried in multicast label mapping message and returns to head node.Like this, head node has just obtained the multicast label that main multicast label distributor is this multicast FEC distribution.

Taking Fig. 1 as example, R1 is head node, suppose that R2 is configured and is chosen as main multicast label distributor, multicast group address is 10.1.1.100, the multicast label that head node is initiated is distributed embodiment of the present invention multicast label assigning process figure as shown in Figure 2, first R1 sends multicast label request message to R2, wherein carry multicast group address: 10.1.1.100, and multicast source address: 255.1.1.1, R2 receives after the multicast label request message of R1, determine not yet for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark distributes multicast label, therefore in all unappropriated multicast label, select a multicast label, for example 60091, this multicast label is carried in multicast label mapping message and returns to R1, thereby R1 obtains the multicast label that main multicast label distributor distributes for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark: 60091.

Based on the finiteness of multicast label, need to reclaim in time multicast label.In the time that multicast forward table corresponding to the multicast FEC of multicast transfer path in the head node of multicast transfer path is aging, need synchronous multicast label corresponding to this multicast forward table of deleting to transmit, simultaneously, can also send to main multicast label distributor the multicast label release message of the multicast FEC information of carrying multicast transfer path, the multicast label that main multicast label distributor receives head node discharges after message, can discharge the multicast label of distributing for this multicast FEC before this.When in transmission node and/or tail node in multicast transfer path, when multicast forward table that the multicast FEC of multicast transfer path is corresponding is aging, need synchronous multicast label corresponding to this multicast forward table of deleting to transmit.

Again, refreshing with burin-in process of multicast label described:

In order to ensure multicast label consistency and the service efficiency in network, main multicast label distributor need to refresh and burin-in process distributing to the multicast label of each multicast FEC.

For this reason, main multicast label distributor is that each multicast FEC distributes after multicast label, can be recorded as the multicast label that this multicast FEC distributes, and this multicast label is refreshed and burin-in process.The head node of multicast transfer path, obtaining after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, also can record this multicast label, and this multicast label is refreshed and burin-in process.

Head node can be as follows with burin-in process to refreshing of multicast label:

The head node of multicast transfer path obtains after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, second ageing time (for example 360 seconds) of this multicast label is set, and after this for example, sending multicast label request message every the second Preset Time (120 seconds) to main multicast label distributor, if receive the multicast label mapping message that main multicast label router returns in the second ageing time, refresh the second ageing time of this multicast label, if do not receive the multicast label mapping message that main multicast label router returns in the second ageing time, delete this multicast label.In addition, here, the second Preset Time should be less than the second ageing time, and this second ageing time can preset in multicast label distributor, and be carried at the head node that sends to multicast transfer path in multicast label mapping message, also can in the head node of multicast transfer path, preset.

In actual realization, in the multicast label request message that head node sends every the second Preset Time, can only carry multicast FEC information, not carry the multicast label information of having distributed to this multicast FEC; Also can carry multicast FEC information simultaneously and distribute to the multicast label information of this multicast FEC.

Correspondingly, according to the content difference of carrying in multicast label request message, main multicast label distributor can be carried out different processing.If only carried multicast FEC information in the multicast label request message that main multicast label distributor receives, and do not carry the multicast label information of distributing to this multicast FEC, can look for the multicast label that this multicast FEC distributes, if do not find, explanation is not yet that this multicast FEC distributes multicast label, need within the scope of multicast label, select a unappropriated multicast label to distribute to this multicast FEC, and this multicast label is carried in multicast label mapping message and returns to head node, if find, explanation has been that this multicast FEC distributes multicast label, therefore, only the multicast label finding need be carried in multicast label mapping message and return to head node.If carried multicast FEC information in the multicast label request message that main multicast label distributor receives and distributed to the multicast label information of this multicast FEC simultaneously, can directly the multicast label information of carrying in multicast label request message be carried in multicast label mapping message and return to head node.

In addition, main multicast label distributor receives the multicast label request message that carries multicast FEC information that head node is sent, and be that this multicast FEC distributes after multicast label, can record the corresponding relation of this multicast FEC and multicast label, and the ageing time (for example 360 seconds) of this corresponding relation is set, if again receive the multicast label request message that this head node is sent in the ageing time of this corresponding relation, can refresh the ageing time of this corresponding relation, otherwise, delete this corresponding relation and discharge this multicast label.Here, the ageing time of the multicast FEC that main multicast label distributor arranges and the corresponding relation of multicast label, can preset, should be greater than the second Preset Time, preferably, be greater than or equal to the second ageing time, to avoid multicast label distributor to discharge multicast label, and each multicast LSR on multicast label path not yet deletes the situation of this multicast label and occurs.

BSR detects former main multicast label distributor fault, and selects after the main multicast label distributor that makes new advances, does not record former main multicast label distributor and distributed to the multicast label of each multicast FEC in new main multicast label distributor.On the other hand, the head node of multicast transfer path has obtained the multicast label of the multicast FEC distribution that former main multicast label distributor is multicast transfer path, and carry out follow-up multicast label notice and multicast label and transmitted the operations such as foundation, if the main multicast label distributor that again please look for novelty is this multicast FEC distribution multicast label, can cause the multicast label in network inconsistent, and can cause flow interrupt, therefore the multicast label of originally having distributed to this multicast FEC is still distributed this multicast FEC by the main multicast label distributor that, need to please look for novelty.

For this reason, when receiving, the head node of multicast transfer path detects after new main multicast label distributor, can send and carry the multicast FEC information of multicast forwarding path and distributed to the multicast label request message of the multicast label information of this multicast FEC to new main multicast label distributor, new main multicast label distributor receives after this multicast label request message of head node, record the corresponding relation of this multicast FEC and multicast label, and the ageing time of this corresponding relation is set, return to the multicast label mapping message that carries the multicast label information of distributing to this multicast FEC simultaneously, thereby make new main multicast label distributor will originally distribute the multicast label of this multicast FEC still to distribute to this multicast FEC.After this, head node is by carrying out the mutual of multicast label request message and multicast label mapping message with new main multicast label distributor, so that the multicast label of distributing to this multicast FEC is refreshed and burin-in process.

In addition, head node obtains after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, this multicast label can be noticed to the each downstream neighbor multicast LSR to self, each downstream neighbor multicast LSR obtains after the multicast label that main multicast label distributor is this multicast FEC distribution, can continue this multicast label to notice the each downstream neighbor multicast LSR to self, the like, until all multicast LSR in multicast transfer path all obtain the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path.

Each multicast LSR can, by sending multicast label notification packet, carry out multicast label notice to the each downstream neighbor multicast LSR of self.The multicast label notification packet here can be a multicast message that TTL is 1, can carry multicast FEC information and distributed to the multicast label information of this multicast FEC in multicast label notification packet.

Referring to Fig. 3, Fig. 3 is embodiment of the present invention multicast label announcement process figure, and Fig. 3 is based on Fig. 1, and wherein, R1 has obtained the multicast label that R2 distributes for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark: 60091.So, the announcement process of this multicast label is as follows:

R1 determines and has a downstream neighbor multicast LSR:R2 according to multicast forward table, therefore sends multicast label notification packet to R2, carries multicast group address: 10.1.1.100, multicast source address: 255.1.1.1 in message, and multicast label 60091;

R2 receives after the multicast label notification packet of R1, obtain the multicast label that R2 distributes for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark: 60091, then determine and have 2 downstream neighbor multicast LSR:R3 and R4 according to multicast forward table, therefore, decibel sends multicast label notification packet to R3 and R4;

R3, R4 receive after the multicast label message of R2, obtain the multicast label that R2 distributes for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark: 60091; Because R3 and R4 do not exist downstream neighbor multicast LSR, therefore all send multicast label confirmation message to R2;

R2 receives after the multicast label confirmation message of R3 and R4, sends multicast label confirmation message to R1;

R1 receives after the multicast label confirmation message of R2, and multicast label has been noticed.

In said process, R2, R3, R4 have finally all obtained the multicast label that R2 distributes for the multicast FEC taking multicast group: 10.1.1.100 and multicast source: 255.1.1.1 as mark: 60091.

In actual applications, the each multicast LSR in multicast transfer path, obtaining after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, all needs this multicast label to refresh and burin-in process.

Can utilize the head node of multicast transfer path regularly to send multicast label notification packet triggers the multicast FEC that other the each node on multicast transfer path is multicast transfer path to the main multicast label distributor obtaining and distributes multicast label to refresh and burin-in process.

The head node of multicast transfer path is obtaining after the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, can for example, send multicast label notification packet every the 3rd Preset Time (60 seconds) to the each downstream neighbor multicast LSR of self and carry out multicast label notice, when each downstream neighbor multicast LSR receives the multicast label notification packet of upstream neighbor multicast LSR transmission first, obtaining the main multicast label distributor carrying in multicast label notification packet is the multicast label that this multicast FEC distributes, and the 3rd ageing time (for example 180 seconds) of this multicast label is set, in the 4th ageing time, again receive the multicast label notification packet that upstream neighbor multicast LSR sends if follow-up, can refresh the 4th ageing time of this multicast label, do not receive if exceed the 4th ageing time the multicast label notification packet that upstream neighbor multicast LSR sends, can delete this multicast label.In addition, each downstream neighbor multicast LSR is receiving after the multicast label notification packet of upstream neighbor multicast LSR transmission, can also continue to send multicast label notification packet to the each downstream neighbor multicast LSR of self, make the each downstream neighbor multicast LSR of self also can obtain the multicast label that the main multicast label distributor carrying in multicast label notification packet is this multicast FEC distribution, and the 4th ageing time of this multicast label is set, and according to whether again receive refreshing and burin-in process that multicast label notification packet that upstream neighbor multicast LSR sends carries out this multicast label in the 4th ageing time, the like, thereby the multicast label of the multicast FEC distribution that all multicast LSR in multicast transfer path can be all multicast transfer path to the main multicast label distributor obtaining is refreshed and burin-in process, to ensure multicast label consistency and the service efficiency in network.Here, the 3rd Preset Time should be less than the 3rd ageing time, the 3rd ageing time can preset in the head node of multicast transfer path, and is carried in multicast label notification packet and sends to downstream multicast LSR, also can on each multicast LSR of multicast transfer path, preset.

Finally, the forwarding of the foundation to multicast LSP and multicast data message describes:

In the embodiment of the present invention multicast label announcement process shown in Fig. 3, can set up multicast label and transmit, in order to carry out the forwarding of multicast data message.Multicast label notice and multicast label transmit the complete procedure of foundation can be as follows:

Head node obtains the multicast label of the multicast FEC distribution that main multicast label distributor is multicast transfer path, determine all downstream neighbor multicast LSR according to the multicast forward table of this multicast FEC, if there is no downstream neighbor multicast LSR, setting up the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC transmits, if there is downstream neighbor multicast LSR, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message that all downstream neighbor multicast LSR return, setting up the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC transmits.

Correspondingly, forward node and/or tail node receive after the multicast label notification packet of upstream neighbor multicast LSR transmission, can obtain the multicast label information of distributing to this multicast FEC of carrying in multicast label notification packet, determine all downstream neighbor multicast LSR according to the multicast forward table of this multicast FEC, if there is no downstream neighbor multicast LSR, set up the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC and transmit, and return to multicast label confirmation message; If there is downstream neighbor multicast LSR, send multicast label notification packet to each downstream neighbor MLR, receive after the multicast label confirmation message that all downstream neighbor multicast LSR return, set up the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC and transmit, and return to multicast label confirmation message.

After each multicast LSR in multicast transfer path sets up multicast label and transmits, multicast LSP sets up.

Transmit in the process of foundation in above-mentioned multicast label notice and multicast label, tail node is set up at first multicast label and is transmitted, head node is finally set up multicast label and is transmitted, final from all tail node to setting up complete multicast LSP head node, like this, can avoid multicast data message to lose.

It should be noted that, in actual applications, same multicast LSR can be simultaneously as head node, forward node, and/or tail node, for example, suppose that certain multicast LSR is the node (being also Designated Router) being directly connected with multicast source on multicast transfer path, this multicast LSR has three outgoing interfaces, if what these three outgoing interfaces connected is multicast LSR, this multicast LSR is only as head node, if what have at least one interface connection in these three interfaces is multicast receivers, this multicast LSR is simultaneously as head node and tail node, if what have at least one interface connection in these three outgoing interfaces is multicast receivers, that also have at least one interface connection is multicast LSR, this multicast LSR is simultaneously as head node, tail node, forward node.

After multicast LSP sets up, for head node, it receives after multicast data message, need to transmit from each outgoing interface and forward according to multicast label, if that this outgoing interface connects is multicast LSR, after need to being pressed into corresponding multicast label in multicast data message, forward from this outgoing interface, if that this outgoing interface connects is not multicast LSR, what this outgoing interface connection was described is multicast receivers or the multicast router of not supporting label forwarding, therefore needs multicast data message directly to forward from this outgoing interface.For forward node and/or tail node, it receives after multicast data message, need to transmit from each outgoing interface and forward according to multicast label, if that this outgoing interface connects is multicast LSR, owing to having carried multicast label in multicast data message, again because all multicast LSR share a multicast label, therefore do not need to carry out label exchange, directly forward from this outgoing interface, if that this outgoing interface connects is not multicast LSR, what this outgoing interface connection was described is multicast receivers or the multicast router of not supporting label forwarding, therefore need multicast data message, therefore after needing the multicast label in multicast data message to eject, forward from this outgoing interface again.

For this reason, in the embodiment of the present invention, defined three kinds of tag operational:

Be pressed into (push), represent that be pressed into multicast label forwards from outgoing interface after multicast data message.Illustrate that current device is the head node being directly connected with multicast source, and the upstream device that this outgoing interface connects is multicast LSR;

Forward (go), represent the multicast label of multicast data message not to be modified, directly from outgoing interface forwarding multicasting label data message.If current device is head node, illustrate that the upstream device that this outgoing interface connects is multicast receivers or the multicast router of not supporting label forwarding; If current device is not head node, illustrate that the upstream device that this outgoing interface connects is multicast LSR;

Eject (pop), after representing the multicast label in multicast data message to eject, forward from outgoing interface.Illustrate that the upstream device that this outgoing interface connects is multicast receivers or the multicast router of not supporting label forwarding.

Therefore, transmit in the process of foundation in above-mentioned multicast label notice and multicast label, head node is set up the method that the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC transmit and is specifically as follows: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to push, otherwise the tag operational that this outgoing interface is corresponding is set to go.

Correspondingly, forward node and/or tail node are set up the method that the multicast label that is associated with this multicast label corresponding to multicast forward table of this multicast FEC transmit and are specifically as follows: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to go, otherwise the tag operational that this outgoing interface is corresponding is set to pop.

Multicast label is transmitted middle content can be as shown in Table 1:

Table one

Wherein, because multicast label is that main multicast label distributor is that multicast FEC distributes, multicast FEC has again corresponding multicast forward table, and therefore, multicast label is transmitted with multicast forward table has corresponding relation.Ageing time is the ageing time that this multicast label is transmitted.Incoming interface is consistent with incoming interface and outgoing interface in multicast forward table with each outgoing interface, and tag operational is whether what to connect according to each outgoing interface be multicast LSR and definite tag operational corresponding to this outgoing interface.

In addition, when arbitrary multicast LSR in multicast transfer path detects new outgoing interface, need to carry out multicast label notice, and in multicast forward table, increase the multicast forwarding list item that this new outgoing interface is corresponding, transmit and increase this new outgoing interface and tag operational corresponding to this new outgoing interface in multicast label, detect need to delete original outgoing interface time, need to from multicast forward table, delete the multicast forwarding list item that this original outgoing interface is corresponding, transmit and delete this original outgoing interface and tag operational corresponding to this original outgoing interface from multicast label.Detailed process can be as follows:

When current multicast LSR detects new outgoing interface, set up the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send multicast label notification packet to this multicast LSR, receiving after the multicast label confirmation message that this multicast LSR returns, set up the label forwarding list item that is associated with corresponding multicast label that this outgoing interface is corresponding and transmit this outgoing interface of middle increase in multicast label, if current multicast LSR is head node, the tag operational corresponding to this outgoing interface of the label forwarding list item of foundation is set to push, if current multicast LSR is forward node and/or tail node, the tag operational corresponding to this outgoing interface of the label forwarding list item of foundation is set to go, , if what this outgoing interface connected is multicast receivers or the multicast router of not supporting label forwarding, transmit this outgoing interface of middle increase in multicast label and set up the label forwarding list item that is associated with corresponding multicast label that this outgoing interface is corresponding, if current multicast LSR is head node, the tag operational corresponding to this outgoing interface of the label forwarding list item of foundation is set to go, if current multicast LSR is forward node and/or tail node, the tag operational corresponding to this outgoing interface of the label forwarding list item of foundation is set to pop,

Current multicast LSR detects need to delete original outgoing interface time, deletes the multicast forwarding list item that in multicast forward table, this place's interface is corresponding, and delete multicast label transmit in this outgoing interface and tag operational corresponding to this outgoing interface.

In addition, transmit multicast data forwarding message according to multicast label, in fact namely transmitting according to multicast label, tag operational corresponding to each outgoing interface carried out different processing and forwarding.For arbitrary outgoing interface, if tag operational corresponding to this outgoing interface is push, multicast label transmitted after associated multicast label is pressed into this multicast data message and forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is go, this multicast data message is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is pop, after the multicast label in this multicast data message being ejected, forward from this outgoing interface.

Based on previously described schematic illustration, in the embodiment of the present invention, provide the method for forwarding multicast message based on MPLS.

Referring to Fig. 4, Fig. 4 is the schematic flow sheet of the method for forwarding multicast message of the embodiment of the present invention based on MPLS, comprises the following steps:

Step 401, current multicast LSR be as the head node of multicast transfer path, the multicast label that the multicast FEC that to obtain main multicast label distributor that BootStrap Router BSR selects be multicast transfer path distributes; Determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, set up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmit, transmit multicast data forwarding message according to multicast label; Otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, set up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmit, transmit multicast data forwarding message according to multicast label.

Step 402, current multicast LSR, as forward node and/or the tail contact of multicast transfer path, receive after the multicast label notification packet of upstream neighbor multicast LSR, obtain the multicast label of distributing for described multicast FEC of carrying in multicast label notification packet; Determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, upstream neighbours' multicast LSR sends multicast label confirmation message, and the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmit, transmit multicast data forwarding message according to multicast label; Otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, upstream neighbours' multicast LSR sends multicast label confirmation message, and the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmit, transmit multicast data forwarding message according to multicast label.

Shown in Fig. 4, in the embodiment of the present invention, described multicast FEC, taking multicast group information as mark, has relation one to one with described multicast group; Or described multicast FEC, taking multicast group and information about multicast source as mark, has relation one to one with described multicast group and multicast source.

The method of the multicast label that the multicast FEC that the main multicast label distributor that the described BSR of obtaining selects is multicast transfer path distributes is specifically as follows: send the multicast label request message that carries described multicast FEC information to main multicast label distributor, receive the multicast label mapping message that main multicast label distributor returns, in described multicast label mapping message, carried main multicast label distributor and received the multicast label of distributing for described multicast FEC after described multicast label request message.

Shown in Fig. 4, in the embodiment of the present invention, in network, configure at least one multicast label distributor;

Each multicast label distributor can send multicast label distributor notification packet, the address information of carrying this multicast label distributor in described multicast label distributor notification packet to BSR every the first Preset Time; If need to according to priority select main multicast label distributor, can also carry the precedence information of this multicast label distributor.

BSR selects the method for main multicast label distributor to be specifically as follows: receive the multicast label distributor notification packet that all multicast label distributors send, obtain and store the address information of each multicast label distributor, select one of them as main multicast label distributor, and the main multicast label distributor of selecting is flooded in network.

In addition, in described multicast label distributor notification packet, can also carry the first ageing time;

Like this, in the time of the address information of the each multicast label distributor of storage, the first ageing time of this multicast label distributor can also be further set, if again receive the multicast label distributor notification packet of this multicast label distributor in the first ageing time, refresh this first ageing time, otherwise, determine this multicast label distributor fault, if the multicast label distributor of this fault is main multicast label distributor, in the multicast label distributor of all not faults, select a main multicast label distributor that conduct is new, and new main multicast label distributor is flooded in network,

Correspondingly, current multicast LSR is as the head node of multicast group, when new main multicast label distributor detected, need to send to new main multicast label distributor the multicast label request message of the multicast label of carrying described multicast FEC information and distribute for described multicast FEC, receive the multicast label mapping message that new main multicast label distributor returns, in described multicast label mapping message, carry the multicast label for described multicast FEC distribution that new main multicast label distributor carries in the described multicast label request message receiving.

Shown in Fig. 4, in the embodiment of the present invention, in described multicast label mapping message, can also carry the second ageing time;

Current multicast LSR is as the head node of multicast transfer path, obtain main multicast label distributor and be after the multicast label that described multicast FEC distributes, further comprise: the second ageing time that this multicast label is set, send the multicast label request message that carries described multicast FEC information to main multicast label distributor every the second Preset Time, if receive the multicast label mapping message that carries the multicast label of distributing to described multicast FEC that main multicast label distributor returns, refresh the second ageing time of this multicast label, otherwise, delete this multicast label; Wherein, described the second Preset Time is less than the second ageing time.

Shown in Fig. 4, in the embodiment of the present invention, in described multicast label notification packet, can also carry the 3rd ageing time;

Current multicast LSR is as the head node of multicast transfer path, and the method that sends multicast label notification packet to each downstream neighbor multicast LSR is: send multicast label notification packet every the 3rd Preset Time to this downstream neighbor multicast LSR;

In addition, current multicast LSR is as forward node and/or the tail contact of multicast transfer path, obtain after the multicast label for described multicast FEC distribution of carrying in multicast label notification packet, further comprise: the 3rd ageing time that this multicast label is set, if again receive the multicast label notification packet that upstream neighbor multicast LSR sends in the 3rd ageing time, refresh the 3rd ageing time of this multicast label, and send multicast label notification packet to the each downstream neighbor multicast LSR of self, otherwise, delete this multicast label; Described the 3rd Preset Time is less than the 3rd ageing time.

In addition,, when this multicast label of described deletion, the multicast label that also needs further deletion to be associated with this multicast label is transmitted.

Shown in Fig. 4 in the embodiment of the present invention, current multicast LSR is as the head node of multicast transfer path, setting up the method that the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC transmit can be: for the each outgoing interface in multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to push, otherwise the tag operational that this outgoing interface is corresponding is set to go;

Correspondingly, current multicast LSR is as forward node and/or the tail contact of multicast transfer path, setting up the method that the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC transmit can be: for the each outgoing interface in multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to forward go, otherwise the tag operational that this outgoing interface is corresponding is set to pop.

Preferably, the method can further include: current multicast LSR is as the head node of multicast transfer path, when new outgoing interface detected, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send multicast label notification packet to this multicast LSR, receive after the multicast label confirmation message that this multicast LSR returns, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to push, otherwise, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to go,

Equally, current multicast LSR is as forward node and/or the tail node of multicast transfer path, when new outgoing interface detected, set up the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send multicast label notification packet to this multicast LSR, receive after the multicast label confirmation message that this multicast LSR returns, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to go, otherwise, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to pop,

In addition, current multicast LSR detects need to delete original outgoing interface time, no matter current multicast LSR is head node, forwarding node or caudal knot point, all need to delete the multicast forwarding list item that in multicast forward table, this original outgoing interface is corresponding, and delete multicast label transmit in this original outgoing interface and tag operational corresponding to this original outgoing interface.

Shown in Fig. 4 in the embodiment of the present invention, the described method according to Label Forwarding Information Base multicast data forwarding message is specifically as follows: for the each outgoing interface in Label Forwarding Information Base, if the tag operational that this outgoing interface is corresponding is push, this multicast label is transmitted to associated multicast label and be pressed into multicast data message, the multicast data message that has been pressed into multicast label is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is go, multicast data message is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is pop, the multicast label in multicast data message is ejected, the multicast data message that has ejected multicast label is forwarded from this outgoing interface.

The present invention also provides a kind of multicast LSR, and this multicast LSR is a node of multicast transfer path, describes below in conjunction with Fig. 5.

Referring to Fig. 5, Fig. 5 is the structural representation of a kind of multicast LSR of the embodiment of the present invention, and this multicast LSR comprises: label acquiring unit 501, label notification unit 502, table are set up unit 503, message repeating unit 504; Wherein,

Label acquiring unit 501, for obtaining the multicast label of the multicast FEC distribution that the main multicast label distributor of BootStrap Router BSR selection is multicast transfer path;

Label notification unit 502, for obtaining at label acquiring unit 501 after the multicast label that main multicast label distributor is described multicast FEC distribution, determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, set up unit 503 to table and send the first notice, otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, set up unit 503 to table and send the first notice;

Table is set up unit 503, for receiving after the first notice of label notification unit 502, sets up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmits;

Message repeating unit 504, for transmitting multicast data forwarding message according to described multicast label.

Preferably, described multicast FEC is taking multicast group information as mark; Or described multicast FEC is taking multicast group and information about multicast source as mark;

Described label acquiring unit 501 obtain main multicast label distributor be described multicast FEC distribute multicast label time, be used for: send the multicast label request message that carries described multicast FEC information to main multicast label distributor, receive the multicast label mapping message that main multicast label distributor returns, in described multicast label mapping message, carried main multicast label distributor and received the multicast label of distributing for described multicast FEC after described multicast label request message.

Preferably, described label acquiring unit 501, when to new main multicast label distributor, send the multicast label request message of the multicast label of carrying described multicast FEC information and distribute for described multicast FEC to new main multicast label distributor, receive the multicast label mapping message that new main multicast label distributor returns, in described multicast label mapping message, carry the multicast label of distributing for described multicast FEC of carrying in the described multicast label request message that new main multicast label distributor receives.

For multicast label is refreshed and burin-in process, keep consistency and the validity of multicast label, in described multicast label mapping message, also carry the second ageing time;

Described label acquiring unit 501 is obtaining after the multicast label that main multicast label distributor is described multicast FEC distribution, be further used for: the second ageing time that this multicast label is set, send the multicast label request message that carries described multicast FEC information to main multicast label distributor every the second Preset Time, if receive the multicast label mapping message that carries the multicast label of distributing to described multicast FEC that main multicast label distributor returns, refresh the second ageing time of this multicast label, otherwise, delete this multicast label; Described the second Preset Time is less than the second ageing time.

In addition, in described multicast label notification packet, also carry the 3rd ageing time;

Described label notification unit 502, while sending multicast label notification packet to each downstream neighbor multicast LSR, be used for: send multicast label notification packet every the 3rd Preset Time to this downstream neighbor multicast LSR, with so that this downstream multicast LSR obtaining after the multicast label of distributing for described multicast FEC, the 3rd ageing time of this multicast label is set, and determines and refresh the 3rd ageing time of this multicast label or delete this multicast label according to the multicast label notification packet that whether again receives upstream neighbor multicast LSR in the 3rd ageing time; Described the 3rd Preset Time is less than the 3rd ageing time.

In addition, when this multicast label of described deletion, the multicast label that also needs further deletion to be associated with this multicast label is transmitted.

Preferably, described table is set up unit 503 in the time that the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmitted, be used for: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to push, otherwise the tag operational that this outgoing interface is corresponding is set to go.

In the time new outgoing interface being detected, need to carry out the notice of multicast label, in multicast forward table, add the multicast forwarding list item that new outgoing interface is corresponding, and transmit this new outgoing interface of middle interpolation and tag operational corresponding to this new outgoing interface in multicast label, thereby set up the multicast LSP that leads to this outgoing interface.In the time that needs are deleted original outgoing interface, equally also need to carry out corresponding deletion action.

For this reason, described table is set up unit 503, when to new outgoing interface, set up the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send the second notice to label notification unit 502, receive after the third notice of label notification unit 502, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to push, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to go; When deleting original outgoing interface to needs, delete multicast forwarding list item corresponding to this original outgoing interface in multicast forward table, and delete multicast label transmit in this original outgoing interface and tag operational corresponding to this original outgoing interface;

Described label notification unit 502, set up for receiving table after the second notice of unit 503, the multicast LSR connecting to described new outgoing interface sends multicast label notification packet, receive after the multicast label confirmation message that multicast LSR that described new outgoing interface connects returns, set up unit 503 to table and send third notice.

In actual realization, described message repeating unit 504 is when according to Label Forwarding Information Base multicast data forwarding message, be used for: each outgoing interface of transmitting for multicast label, if the tag operational that this outgoing interface is corresponding is push, this multicast label is transmitted to associated multicast label and be pressed into multicast data message, the multicast data message that has been pressed into multicast label is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is go, multicast data message is forwarded from this outgoing interface.

The present invention also provides another kind of multicast LSR, and this multicast LSR is forward node and/or the tail node of multicast transfer path, describes below in conjunction with Fig. 6.

Referring to Fig. 6, Fig. 6 is the structural representation of the another kind of multicast LSR of the embodiment of the present invention, and this multicast LSR comprises: label acquiring unit 601, label notification unit 602, table are set up unit 603, message repeating unit 604; Wherein,

Label acquiring unit 601, the multicast label of distributing for receiving the multicast label notification packet of upstream neighbor multicast LSR, obtain multicast FEC that the main multicast label distributor that carries in multicast label notification packet is multicast transfer path; After knowing for the four-way that receives label notification unit 602, upstream neighbours' multicast LSR sends multicast label confirmation message;

Label notification unit 602, for being retrieved as at label acquiring unit 601 after the multicast label of described multicast FEC distribution, determine all downstream neighbor multicast LSR according to the multicast forward table of described multicast FEC, if there is no downstream neighbor multicast LSR, sending four-way to label acquiring unit 601 knows, and set up unit 603 to table and send five-way and know, otherwise, send multicast label notification packet to each downstream neighbor multicast LSR, receive after the multicast label confirmation message of all downstream neighbor multicast LSR, sending four-way to label acquiring unit 601 knows, and set up unit 603 to table and send five-way and know,

Table is set up unit 603, for after receiving the five-way of label notification unit 602 and knowing, sets up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmits;

Message repeating unit 604, for transmitting multicast data forwarding message according to described multicast label.

Preferably, described multicast FEC is taking multicast group information as mark; Or described multicast FEC is taking multicast group and information about multicast source as mark.

For multicast label is refreshed and burin-in process, keep consistency and the validity of multicast label, in described multicast label notification packet, also carry the 3rd ageing time;

Described label acquiring unit 601, the multicast label notification packet of sending every the 3rd Preset Time for receiving upstream neighbor multicast LSR; Obtaining after the multicast label that multicast FEC that the main multicast label distributor that carries in multicast label notification packet is multicast transfer path distributes, be further used for: the 3rd ageing time that this multicast label is set, if again receive the multicast label notification packet of upstream neighbor multicast LSR in the 3rd ageing time, refresh the 3rd ageing time of this multicast label, and send multicast label notification packet to the each downstream neighbor multicast LSR of self, otherwise, delete this multicast label; Described the 3rd Preset Time is less than the 3rd ageing time.

In addition, described label acquiring unit 601 is in the time of this multicast label, and the multicast label that also needs further deletion to be associated with this multicast label is transmitted.

Preferably, described table is set up unit 603 in the time that the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmitted, be used for: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to forward go, otherwise the tag operational that this outgoing interface is corresponding is set to eject pop.

In the time new outgoing interface being detected, need to carry out the notice of multicast label, in multicast forward table, add the multicast forwarding list item that new outgoing interface is corresponding, and transmit this new outgoing interface of middle interpolation and tag operational corresponding to this new outgoing interface in multicast label, thereby set up the multicast LSP that leads to this new interface.In the time that needs are deleted original outgoing interface, equally also need to carry out corresponding deletion action.

For this reason, described table is set up unit 603, when to new outgoing interface, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send the 6th notice to label notification unit 602, receive after the 7th notice of label notification unit 602, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to go, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to pop; When deleting original outgoing interface to needs, delete multicast forwarding list item corresponding to this original outgoing interface in multicast forward table, and delete multicast label transmit in this original outgoing interface and tag operational corresponding to this original outgoing interface;

Described label notification unit 602, set up for receiving table after the 6th notice of unit 603, the multicast LSR connecting to new outgoing interface sends multicast label notification packet, receive after the multicast label confirmation message that multicast LSR that new outgoing interface connects returns, set up unit 603 to table and send the 7th notice.

In reality realizes, described message repeating unit 604 is when according to Label Forwarding Information Base multicast data forwarding message, be used for: each outgoing interface of transmitting for multicast label, if tag operational corresponding to this outgoing interface is go, forwards multicast data message from this outgoing interface; If the tag operational that this outgoing interface is corresponding is pop, the multicast label in multicast data message is ejected, the multicast data message that has ejected multicast label is forwarded from this outgoing interface.

The foregoing is only preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any amendment of making, be equal to replacement, improvement etc., within all should being included in the scope of protection of the invention.

Claims

1. the multicast data packet forwarding method based on multiprotocol label switching MPLS, is characterized in that, the method comprises:

2. the multicast data packet forwarding method based on MPLS according to claim 1, is characterized in that,

Described multicast FEC is taking multicast group information as mark; Or described multicast FEC is taking multicast group and information about multicast source as mark;

The method of the multicast label that the multicast FEC that the main multicast label distributor that the described BSR of obtaining selects is multicast transfer path distributes is: send the multicast label request message that carries described multicast FEC information to main multicast label distributor, receive the multicast label mapping message that main multicast label distributor returns, in described multicast label mapping message, carried main multicast label distributor and received the multicast label of distributing for described multicast FEC after described multicast label request message.

3. the multicast data packet forwarding method based on MPLS according to claim 2, is characterized in that, configures at least one multicast label distributor;

Each multicast label distributor sends multicast label distributor notification packet, the address information of carrying this multicast label distributor in described multicast label distributor notification packet every the first Preset Time to BSR;

BSR selects the method for main multicast label distributor to be: receive the multicast label distributor notification packet that all multicast label distributors send, obtain and store the address information of each multicast label distributor, select one of them as main multicast label distributor, and the main multicast label distributor of selecting is flooded in network.

4. the multicast data packet forwarding method based on MPLS according to claim 3, is characterized in that,

In described multicast label distributor notification packet, also carry the first ageing time;

While storing the address information of each multicast label distributor, the first ageing time of this multicast label distributor is further set, if again receive the multicast label distributor notification packet of this multicast label distributor in the first ageing time, refresh the first ageing time of this multicast label distributor, otherwise, determine this multicast label distributor fault, if the multicast label distributor of this fault is main multicast label distributor, in the multicast label distributor of all not faults, select a main multicast label distributor that conduct is new, and new main multicast label distributor is flooded in network,

Current multicast LSR is as the head node of multicast group, when new main multicast label distributor detected, send the multicast label request message of the multicast label of carrying described multicast FEC information and distribute for described multicast FEC to new main multicast label distributor, receive the multicast label mapping message that new main multicast label distributor returns, in described multicast label mapping message, carry the multicast label for described multicast FEC distribution that new main multicast label distributor carries in the described multicast label request message receiving.

5. the multicast data packet forwarding method based on MPLS according to claim 2, is characterized in that, in described multicast label mapping message, also carries the second ageing time;

Current multicast LSR is as the head node of multicast transfer path, obtain main multicast label distributor and be after the multicast label that described multicast FEC distributes, further comprise: the second ageing time that this multicast label is set, send the multicast label request message that carries described multicast FEC information to main multicast label distributor every the second Preset Time, if receive the multicast label mapping message that carries the multicast label of distributing to described multicast FEC that main multicast label distributor returns, refresh the second ageing time of this multicast label, otherwise, delete this multicast label; Described the second Preset Time is less than the second ageing time.

6. the multicast data packet forwarding method based on MPLS according to claim 2, is characterized in that,

In described multicast label notification packet, also carry the 3rd ageing time;

Current multicast LSR is as forward node and/or the tail contact of multicast transfer path, obtain after the multicast label for described multicast FEC distribution of carrying in multicast label notification packet, further comprise: the 3rd ageing time that this multicast label is set, if again receive the multicast label notification packet that upstream neighbor multicast LSR sends in the 3rd ageing time, refresh the 3rd ageing time of this multicast label, and send multicast label notification packet to the each downstream neighbor multicast LSR of self, otherwise, delete this multicast label; Described the 3rd Preset Time is less than the 3rd ageing time.

7. according to the multicast data packet forwarding method based on MPLS described in claim 5 or 6, it is characterized in that,

When this multicast label of described deletion, the multicast label that further deletion is associated with this multicast label is transmitted.

8. the multicast data packet forwarding method based on MPLS according to claim 1, is characterized in that,

Current multicast LSR is as the head node of multicast transfer path, setting up the method that the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC transmit is: for the each outgoing interface in multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to be pressed into push, otherwise the tag operational that this outgoing interface is corresponding is set to forward go;

Current multicast LSR is as forward node and/or the tail contact of multicast transfer path, setting up the method that the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC transmit is: for the each outgoing interface in multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to forward go, otherwise the tag operational that this outgoing interface is corresponding is set to eject pop.

9. the multicast data packet forwarding method based on MPLS according to claim 8, is characterized in that, the method further comprises:

Current multicast LSR is as the head node of multicast transfer path, when new outgoing interface detected, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send multicast label notification packet to this multicast LSR, receive after the multicast label confirmation message that this multicast LSR returns, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to push, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to go,

Current multicast LSR is as forward node and/or the tail node of multicast transfer path, when new outgoing interface detected, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send multicast label notification packet to this multicast LSR, receive after the multicast label confirmation message that this multicast LSR returns, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to go, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to pop,

Current multicast LSR detects need to delete original outgoing interface time, deletes multicast forwarding list item corresponding to this original outgoing interface in multicast forward table, and delete multicast label transmit in this outgoing interface and tag operational corresponding to this outgoing interface.

10. the multicast data packet forwarding method based on MPLS according to claim 8 or claim 9, is characterized in that,

According to the method for Label Forwarding Information Base multicast data forwarding message be: for the each outgoing interface in Label Forwarding Information Base, if the tag operational that this outgoing interface is corresponding is push, the multicast label of this Label Forwarding Information Base association is pressed into multicast data message, the multicast data message that has been pressed into multicast label is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is go, multicast data message is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is pop, the multicast label in multicast data message is ejected, the multicast data message that has ejected multicast label is forwarded from this outgoing interface.

11. 1 kinds of multicast label switch router LSR, this multicast LSR is the head node of multicast transfer path, it is characterized in that, this multicast LSR comprises: label acquiring unit, label notification unit, table are set up unit, message repeating unit;

12. multicast LSR according to claim 11, is characterized in that,

Described label acquiring unit obtain main multicast label distributor be described multicast FEC distribute multicast label time, be used for: send the multicast label request message that carries described multicast FEC information to main multicast label distributor, receive the multicast label mapping message that main multicast label distributor returns, in described multicast label mapping message, carried main multicast label distributor and received the multicast label of distributing for described multicast FEC after described multicast label request message.

13. multicast LSR according to claim 12, is characterized in that,

Described label acquiring unit, when to new main multicast label distributor, send the multicast label request message of the multicast label of carrying described multicast FEC information and distribute for described multicast FEC to new main multicast label distributor, receive the multicast label mapping message that new main multicast label distributor returns, in described multicast label mapping message, carry the multicast label of distributing for described multicast FEC of carrying in the described multicast label request message that new main multicast label distributor receives.

14. multicast LSR according to claim 12, is characterized in that, in described multicast label mapping message, also carry the second ageing time;

Described label acquiring unit is obtaining after the multicast label that main multicast label distributor is described multicast FEC distribution, be further used for: the second ageing time that this multicast label is set, send the multicast label request message that carries described multicast FEC information to main multicast label distributor every the second Preset Time, if receive the multicast label mapping message that carries the multicast label of distributing to described multicast FEC that main multicast label distributor returns, refresh the second ageing time of this multicast label, otherwise, delete this multicast label; Described the second Preset Time is less than the second ageing time.

15. multicast LSR according to claim 12, is characterized in that,

Described label notification unit, while sending multicast label notification packet to each downstream neighbor multicast LSR, be used for: send multicast label notification packet every the 3rd Preset Time to this downstream neighbor multicast LSR, with so that this downstream multicast LSR obtaining after the multicast label of distributing for described multicast FEC, the 3rd ageing time of this multicast label is set, and determines and refresh the 3rd ageing time of this multicast label or delete this multicast label according to the multicast label notification packet that whether again receives upstream neighbor multicast LSR in the 3rd ageing time; Described the 3rd Preset Time is less than the 3rd ageing time.

16. multicast LSR according to claim 14, is characterized in that,

17. multicast LSR according to claim 11, is characterized in that,

Described table is set up unit in the time that the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmitted, be used for: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to be pressed into push, otherwise the tag operational that this outgoing interface is corresponding is set to forward go.

18. multicast LSR according to claim 17, is characterized in that,

Described table is set up unit, when to new outgoing interface, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send the second notice to label notification unit, receive after the third notice of label notification unit, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to push, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to go; When deleting original outgoing interface to needs, delete multicast forwarding list item corresponding to this original outgoing interface in multicast forward table, and delete multicast label transmit in this outgoing interface and tag operational corresponding to this outgoing interface;

Described label notification unit, set up for receiving table after the second notice of unit, the multicast LSR connecting to described new outgoing interface sends multicast label notification packet, receive after the multicast label confirmation message that multicast LSR that described new outgoing interface connects returns, set up unit to table and send third notice.

19. according to the multicast LSR described in claim 17 or 18, it is characterized in that,

Described message repeating unit is when according to Label Forwarding Information Base multicast data forwarding message, be used for: each outgoing interface of transmitting for multicast label, if the tag operational that this outgoing interface is corresponding is push, the multicast label of this Label Forwarding Information Base association is pressed into multicast data message, the multicast data message that has been pressed into multicast label is forwarded from this outgoing interface; If the tag operational that this outgoing interface is corresponding is go, multicast data message is forwarded from this outgoing interface.

20. a multicast label switch router LSR, this multicast LSR is forward node and/or the tail node of multicast transfer path, it is characterized in that, this multicast LSR comprises: label acquiring unit, label notification unit, table are set up unit, message repeating unit;

Described table is set up unit, for after receiving the five-way of label notification unit and knowing, sets up the multicast label that is associated with described multicast label corresponding to multicast forward table of described multicast FEC and transmits;

21. multicast LSR according to claim 20, is characterized in that,

Described multicast FEC is taking multicast group information as mark; Or described multicast FEC is taking multicast group and information about multicast source as mark.

22. multicast LSR according to claim 20, is characterized in that,

Described label acquiring unit, the multicast label notification packet of sending every the 3rd Preset Time for receiving upstream neighbor multicast LSR; Obtaining after the multicast label that multicast FEC that the main multicast label distributor that carries in multicast label notification packet is multicast transfer path distributes, be further used for: the 3rd ageing time that this multicast label is set, if again receive the multicast label notification packet of upstream neighbor multicast LSR in the 3rd ageing time, refresh the 3rd ageing time of this multicast label, and send multicast label notification packet to the each downstream neighbor multicast LSR of self, otherwise, delete this multicast label; Described the 3rd Preset Time is less than the 3rd ageing time.

23. multicast LSR according to claim 22, is characterized in that,

Described label acquiring unit is in the time of this multicast label, and the multicast label that further deletion is associated with this multicast label is transmitted.

24. multicast LSR according to claim 20, is characterized in that,

Described table is set up unit in the time that the multicast label that is associated with described multicast label corresponding to the multicast forward table of setting up described multicast FEC transmitted, be used for: for each outgoing interface of multicast forward table, transmit this outgoing interface of middle interpolation in multicast label, if that this outgoing interface connects is multicast LSR, the tag operational that this outgoing interface is corresponding is set to forward go, otherwise the tag operational that this outgoing interface is corresponding is set to eject pop.

25. multicast LSR according to claim 24, is characterized in that,

Described table is set up unit, when to new outgoing interface, in multicast forward table, add the multicast forwarding list item that this outgoing interface is corresponding, if that this outgoing interface connects is multicast LSR, send the 6th notice to label notification unit, receive after the 7th notice of label notification unit, transmit this outgoing interface of middle interpolation in multicast label, the tag operational that this outgoing interface is corresponding is set to go, otherwise, transmit this outgoing interface of middle interpolation in multicast label, and tag operational corresponding to this outgoing interface is set to pop; When deleting original outgoing interface to needs, delete multicast forwarding list item corresponding to this original outgoing interface in multicast forward table, and delete multicast label transmit in this original outgoing interface and tag operational corresponding to this original outgoing interface;

Described label notification unit, set up for receiving table after the 6th notice of unit, the multicast LSR connecting to new outgoing interface sends multicast label notification packet, receives after the multicast label confirmation message that multicast LSR that new outgoing interface connects returns, and sets up unit send the 7th notice to table.

26. according to the multicast LSR described in claim 24 or 25, it is characterized in that,

Described message repeating unit, when according to Label Forwarding Information Base multicast data forwarding message, for each outgoing interface of transmitting for multicast label, if tag operational corresponding to this outgoing interface is go, forwards multicast data message from this outgoing interface; If the tag operational that this outgoing interface is corresponding is pop, the multicast label in multicast data message is ejected, the multicast data message that has ejected multicast label is forwarded from this outgoing interface.