CN101577679A

CN101577679A - Configuration management method for realizing multicast service sharing among appointed routers and appliance thereof

Info

Publication number: CN101577679A
Application number: CNA2009101485244A
Authority: CN
Inventors: 王伟
Original assignee: Hangzhou H3C Technologies Co Ltd
Current assignee: New H3C Technologies Co Ltd
Priority date: 2009-06-26
Filing date: 2009-06-26
Publication date: 2009-11-11
Anticipated expiration: 2029-06-26
Also published as: CN101577679B

Abstract

The invention discloses a configuration management method for realizing multicast service sharing among appointed routers and an appliance thereof. The method comprises the following steps: state management and establishing primary-backup relationship can be carried out among a plurality of routers determined as DR in a shared network segment by setting up different identities for routers which are determinated as DR in the shared network segment, resource of each router can be fully used, thus realizing sharing of multicast service for the shared network segment among routers, achieving the whole network load balance of multicast service, enlarging multicast processing ability of the shared network segment and improving the multicast processing specification of the shared network segment.

Description

Realize the method for state management and the device of multicast service sharing between the Designated Router

Technical field

The present invention relates to communication technical field, particularly a kind of method of state management and device of realizing multicast service sharing between the Designated Router.

Background technology

(Internet Protocol Television, IPTV), the carrying out of business such as video conference, and the rise of Digital Television, multicast service has obtained application more and more widely on existing network along with IPTV at present.

For user side, using multicast service mainly is that (Internet Group Management Protocol IGMP) waits relevant agreement to realize by multicast routing protocol and IGMP.

When the user needs multicast service, can organize the message that joins request to the IGMP that the router that links to each other sends some multicast group by ustomer premises access equipment, router receives that the IGMP of this multicast group joins request after the message, confirming has the user need obtain the multicast packet business of this multicast group, thereby, according to multicast packet party in request and provider's corresponding relation, form an IGMP list item, and further from current network, the data flow of this multicast group is sent to corresponding user.

For the reliability that guarantees that multicast service is carried out, form backup reliably, the router operated by rotary motion that links to each other with the user has a plurality of, in existing network configuration, generally is two routers to be set directly link to each other with ustomer premises access equipment.Accordingly, the a plurality of routers that link to each other with same ustomer premises access equipment can be by certain competition mechanism, elect a router and be used as requestor, be responsible for the maintenance work of multicast group by this requestor, simultaneously by Protocol Independent Multicast (Protocol Independent Multicast, PIM) router is selected a Designated Router (Designated Router by certain rules of competition, DR), be responsible for the forwarding work of multicast packet by DR.In common typical application scenarios, the PIM and the IGMP that insert side move simultaneously, finish carrying out of multicast service.

Sparse mode (Protocol Independent Multicast-SparseMode with common Protocol Independent Multicast, PIM-SM) be example, the working mechanism of multicast protocol is described, the working mechanism of PIM-SM may be summarized to be neighbours' discovery, DR election, Rendezvous Point (Rendezvous Point, RP) find, make up RP tree (RP Tree, RPT), multicast source registration and shortest path tree (Shortest Path Tree SPT) switches six processes, specifies as follows:

1. neighbours find

PIM-SM carries out the exchange of HELLO message between router, and finds to share neighbours on the network segment with this.

2.DR election

Can also be shared network (for example, Ethernet Ethernet) election DR by the HELLO message, and with the DR that the elects unique forwarding person as multicast packet in this shared network.

In actual applications, no matter be the network that links to each other with multicast source, still the network that links to each other with the recipient all needs to elect corresponding D R.The DR of recipient's side is responsible for joining message to the RP transmission, and the DR of multicast source is responsible for sending logon message to RP.

The election strategy of DR in the prior art is as follows:

(1) each router on the shared network sends the HELLO message each other, carries the priority parameters of this router election contest DR in this HELLO message, and the router that has limit priority will become DR.

(2) if exist a plurality of routers to have identical limit priority, perhaps have at least a router not to be supported in the shared network and carry the priority parameters of campaigning for DR in the HELLO message, then campaign for DR according to the IP address size of each router, the router of IP address maximum will become DR.

(3) when DR breaks down, all the other routers are not still received the HELLO message from DR after exceeding the default response time, then can trigger new DR election process.

In the shared network segment as shown in Figure 1, the multicast source comprises router-A, router B and router C, according to above-mentioned DR election strategy, the router B that election has limit priority becomes DR, and in recipient's side, in router D and router E, elect router D to become DR with limit priority, wherein, router B sends logon message to the router F as RP, and router D sends to RP and joins message.

3.RP find

RP is the nucleus equipment in the pim-sm domain.Generally in pim-sm domain, need to dispose a plurality of candidate RP (Candidate-RP, C-RP), by boot mechanism dynamically elect RP, make different RP serve different multicast group, at this moment, also need to dispose BootStrap Router (BootStrap Router, BSR).BSR is the higher management of pim-sm domain, in the pim-sm domain BSR can only be arranged, but can dispose a plurality of candidate bsrs (Candidate-BSR, C-BSR).Like this, in case BSR breaks down, all the other C-BSR can produce new BSR by automatic election, thereby guarantee that business avoids interrupting.

4. make up RPT

As shown in Figure 2, the building process of RPT is as follows:

Step S201, when the recipient adds a multicast group G, earlier by the IGMP message notifying DR direct-connected with it.

After step s202, DR have grasped recipient's the information of multicast group G, send to the pairing RP direction of this multicast group G hop-by-hop and to join message.

Step S203, from DR to RP the router of process just formed the branch of RPT, these routers have generated in it is transmitted all that (" * " expression here is from any multicast source for *, G) list item.RPT is a root with RP, is leaf with DR.

When the multicast packet that mails to multicast group G was flowed through RP, data will arrive DR along the RPT that has set up, and then arrived the recipient.

When certain recipient was no longer interested in the information of multicast group G, the DR direct-connected with it can send prune packet to the RP direction hop-by-hop of this multicast group G against RPT.Upstream node is received the interface that deletion links to each other with downstream node in its outgoing interface tabulation behind this message, and check whether oneself has the recipient of this multicast group G, if not then continue to transmit this prune packet to its upstream, on the contrary, if this upstream node discovery oneself also has the recipient of other this multicast group G, this prune packet of forwarded upstream no longer then, because, the RPT branch that need continue to keep the upstream for other recipient.。

5. multicast source registration

As shown in Figure 3, multicast source is as follows to the process of RP registration:

Step S301, when multicast source S when multicast group G has sent a multicast message, the DR that directly connects with multicast source just is packaged into logon message with it, and sends to corresponding RP by mode of unicast after receiving this message.

Step S302, after RP receives this message, on the one hand the decapsulation logon message and the multicast message that will be encapsulated in wherein are transmitted to the recipient along RPT, send to multicast source direction hop-by-hop on the other hand that (S G) joins message.Like this, from RP to the multicast source the router of process just formed the branch of SPT, these routers have all generated (S, G) list item in it is transmitted.SPT is a root with the DR of multicast source, is leaf with RP.

The multicast packet that step S303, multicast source send arrives RP along the SPT that has set up, by RP multicast packet is transmitted to the recipient along RPT then.Receive the multicast packet that transmits along SPT as RP after, to sending stopped registration messages (Register-StopMessage) with the direct-connected DR of multicast source, process for registering the multicast source finishes by mode of unicast.

6.SPT switch

Recipient's side DR periodically the test set multicast data (S, forwarding rate G) surpass threshold value in case find it, initiate SPT immediately and switch, and process is as follows:

At first, recipient's side DR to the multicast source direction send (S G) joins message, and finally sends to the DR of multicast source, on the way the all-router of process in it is transmitted, all generated (S, G) list item, thereby set up SPT branch;

Subsequently, when multicast packet when SPT arrives the router of RPT and SPT bifurcated, this router begins to abandon the multicast packet that arrives along RPT, send the prune packet that contains the RP position to the RP hop-by-hop simultaneously, RP continues to send prune packet (supposing to have only this recipient this moment) to the multicast source direction after receiving this message, thereby has finished the SPT switching;

Finally, multicast packet will reach the recipient from multicast source along SPT.

Switch by SPT, PIM-SM can set up SPT in the mode more more economical than PIM-DM.

In realizing process of the present invention, the inventor finds that there is following problem at least in prior art:

In the network architecture structure of prior art, DR is very important in a multicast role, is bearing the important duty such as foundation that multicast source registration and recipient hold RPT and SPT tree.At present, according to the processing rule of PIM agreement, have only a router bearing the role of DR on a shared network segment, all the other routers all are the backup functionalitys as the router of DR.Like this, in case after selecting to determine as the router of DR, the forward-path SPT of multicast has also determined, cause all multicast services just to be finished by the minority router, and remaining router all has been a backup functionality.Along with carrying out of multicast service, the user wishes that all routers can both the forwarding multicasting business, and all like this equipment all are fully used, and the user also wishes by such mode simultaneously, makes the function that backups each other that realizes multicast between each router.

In a typical enterprise network multicast application networking diagram as shown in Figure 4, processing rule according to prior art, inserting side is a shared network segment, the DR that inserts side is not that router B is exactly router C, if determining DR is router B, so the path of multicast data flow be exactly multicast source Source to router-A, arrive router B again, arrive router D again, send to recipient Receiver at last; If DR is router C, so the path of multicast data flow be exactly multicast source Source to router-A, arrive router C again, arrive router D again, send to recipient Receiver at last.

Can see that group business stream is all the time on the link of one side, can't realize of the branch road transmission of the data flow of a part of multicast group by router B place, and the data flow of another part multicast group is by the treatment state of the branch road transmission at router C place, thereby, can't realize the whole network load balancing of multicast service, waste resources a large amount of in the shared network segment.

Summary of the invention

The invention provides a kind of method of state management and device of realizing multicast service sharing between the Designated Router, to realize that many routers are shared multicast service jointly on the shared network segment, make each router can both give full play to the effect of oneself, thereby realize the load balancing of multicast service.

For achieving the above object, one aspect of the present invention provides a kind of method of state management of realizing multicast service sharing between the Designated Router DR, be applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, remaining whole router settings are certainly as work DR, the described main DR that uses, described standby DR and described work DR share multicast service in the described shared network segment jointly according to the strategy of load balancing, and described method specifically comprises:

Described standby DR or described work DR send the cycle according to default calling HELLO message respectively, the router that in the described shared network segment all are confirmed as DR sends the HELLO message, and described HELLO message comprises the current identity state information of described standby DR or described work DR;

Described main with the HELLO message of DR according to described standby DR or described work DR transmission, obtain the current identity state information of described standby DR or described work DR, send the cycle according to described HELLO message, the router that in the described shared network segment all are confirmed as DR sends the main calling Master HELLO message of using, and comprises in the described Master HELLO message according to all are confirmed as the up-to-date identity state information of the router of DR in the definite described shared network segment of described DR election strategy;

Described standby DR and described work DR receive the Master HELLO message that described master sends with DR, and according to the up-to-date identity state information in the described Master HELLO message identity state of self are set.

Preferably, the DR election strategy that described basis is preset, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, and another router setting is certainly as standby DR, and remaining whole router settings as work DR, are specially certainly:

The router that respectively is confirmed as DR in the described shared network segment sends the cycle according to default HELLO message respectively, the router transmission that in the described shared network segment all are confirmed as DR comprises the HELLO message of electing parameter, described election parameter comprises the IP address information at least, and optionally comprises priority parameters;

When the described election parameter that respectively is confirmed as being comprised in the HELLO message that router sent of DR is priority parameters, the described router that respectively is confirmed as DR compares the priority parameters of self and other priority parameters that are confirmed as the router of DR that receive by described HELLO message, if the priority of the priority parameters of self is for the highest, then be provided with from using DR as the master; If the priority of the priority parameters of self is inferior high, then be provided with certainly as standby DR; If the priority of the priority parameters of self is not the highest or inferior high, then be provided with certainly as work DR;

When having at least one to be not priority parameters in the described election parameter that respectively is confirmed as being comprised in the HELLO message that router sent of DR, the described router that respectively is confirmed as DR compares information of self IP address and other IP address informations that are confirmed as the router of DR that receive by described HELLO message, if its own IP address maximum then is provided with from using DR as the master; If its own IP address is inferior big, then be provided with certainly as standby DR; If its own IP address is not maximum or inferior big, then be provided with certainly as work DR.

Preferably, when the default DR election strategy of basis, when election parameter of not supporting the router of many identity state configuration was better than other routers in the described shared network segment in the router of described a plurality of DR of being confirmed as, the described router of not supporting many identity state configuration was born the multicast service in the described shared network segment.

Preferably, described Master HELLO message also comprises:

DR quantity in the described shared network segment;

The identification information of all DR in the described shared network segment;

Whether each DR in the described shared network segment supports the sign of many identity state configuration.

Preferably, described standby DR and described work DR receive the Master that described master sends with DR

The HELLO message, and self identity state is set according to the up-to-date identity state information in the described Master HELLO message, be specially:

When described standby DR did not receive the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, described standby DR was provided with from as the main DR that uses;

When described standby DR receives the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, and when the up-to-date identity state information of the described standby DR that is comprised in the described Master HELLO message was work DR, described standby DR was provided with certainly as work DR;

When described work DR did not receive the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, described work DR was provided with from as the main DR that uses;

When described work DR receives the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, and when the up-to-date identity state information of the described work DR that is comprised in the described Master HELLO message was standby DR, described work DR was provided with from as standby DR;

Wherein, described default standby DR Master HELLO message receiving cycle sends the cycle greater than described HELLO message, less than described preset working DRMaster HELLO message receiving cycle.

Preferably, when new router added the described shared network segment, described method also comprised:

The current identity state information that described new router is provided with self is the DR that reaches the standard grade;

The router that the described DR of reaching the standard grade all in the described shared network segment are confirmed as DR sends current identity state information that comprises self and the HELLO message of electing parameter;

Described master receives with DR after the HELLO message of described current identity state information that comprises the described DR of reaching the standard grade and election parameter, sends the Master HELLO message of the up-to-date identity state information that comprises the described DR of reaching the standard grade that determines according to described DR election strategy and described election parameter to the described DR of reaching the standard grade;

The described DR of reaching the standard grade is provided with the identity state of self according to the up-to-date identity state information in the described Master HELLO message.

The described DR of reaching the standard grade receives that router that in the described shared network segment all are confirmed as DR sends comprises the HELLO message of self election parameter;

The described DR of reaching the standard grade conducts an election according to election parameter and the described DR election strategy that in the described shared network segment all are confirmed as the router of DR, and according to election results the identity state of self is set.

Preferably, the described DR of reaching the standard grade is provided with self identity state according to the up-to-date identity state information in the described Master HELLO message, is specially:

When the described DR of reaching the standard grade did not receive the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade, the described DR of reaching the standard grade was provided with from as the main DR that uses;

When the described DR of reaching the standard grade receives the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade, and when the up-to-date identity state information of the described DR of reaching the standard grade that is comprised in the described Master HELLO message was standby DR or work DR, the described DR that reaches the standard grade was provided with certainly as standby DR or work DR;

Wherein, the described default DR Master HELLO message receiving cycle of reaching the standard grade sends the cycle less than described HELLO message.

Preferably, describedly main share multicast service in the described shared network segment jointly, be specially with DR, described standby DR and described work DR:

Described main DR, described standby DR and the described work DR of using calculates the cryptographic Hash of self respectively by hash function, and described cryptographic Hash of self and other described main cryptographic Hash with DR, described standby DR and described work DR are compared;

When having unique maximum in the described cryptographic Hash, pairing described main usefulness DR, described standby DR of the maximum of described cryptographic Hash or described work DR are as the multicast source or the multicast group of the corresponding described shared network segment of DR;

When having a plurality of maximum in the described cryptographic Hash, described main usefulness DR, the described standby DR of IP address maximum or described work DR are as the multicast source or the multicast group of the corresponding described shared network segment of DR.

On the other hand, the present invention also provides a kind of router, be applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, remaining whole router settings are certainly as work DR, router setting in the described shared network segment of new adding is certainly as the DR that reaches the standard grade, describedly main share multicast service in the described shared network segment jointly, comprising with DR, described standby DR and described work DR:

The message sending module, when the current identity state information of described router is standby DR, work DR or when reaching the standard grade DR, be used for sending the cycle according to default HELLO message, all-router in the described shared network segment sends the HELLO message that comprises self identity state information, when the current identity state information of described router is main when using DR, be used for sending the cycle according to default HELLO message, the router that all in the described shared network segment are confirmed as DR sends the MasterHELLO message of the up-to-date identity state information that comprises in the described shared network segment of determining according to described DR election strategy all routers that are confirmed as DR;

The message receiver module, be used for receiving the HELLO message that other routers that are confirmed as DR of the described shared network segment send, when the current identity state information of described router is standby DR, the DR or when reaching the standard grade DR of working, also be used for receiving the Master HELLO message that the master of the described shared network segment sends with DR;

Module is set, electrically connect with described message receiver module and described message sending module respectively, when described router is current when the identity state of self is not set, be used for the identity state that HELLO message that other routers that are confirmed as DR of the described shared network segment that receives according to described message receiver module send and default DR election strategies are provided with self, when the current identity state information of described router is standby DR, work DR or when reaching the standard grade DR, the up-to-date identity state information that also is used for the MasterHELLO message that received according to described message receiver module is provided with the identity state of self.

Preferably, described router also comprises message detection module and timing module:

Described message detection module, electrically connect with described message receiver module and the described module that is provided with, when the current identity state information of described router is standby DR or work DR, be used for judging whether described message receiver module receives the main Master HELLO message that sends with DR at default standby DR Master HELLO message receiving cycle or work DR MasterHELLO message receiving cycle;

Described timing module, electrically connect with described message detection module, be used for described HELLO message is sent the cycle, and/or described default standby DR Master HELLO message receiving cycle, and/or described preset working DR Master HELLO message receiving cycle, and/or the described default DRMaster HELLO message receiving cycle of reaching the standard grade carries out timing;

In this case:

The described module that is provided with, also to be used for current identity state information when described router be standby DR, DR or when reaching the standard grade DR works, according to the testing result of described message detection module, the identity state that up-to-date identity state information in the Master HELLO message that is received according to described message receiver module and following strategy are provided with self:

Wherein, described default standby DR Master HELLO message receiving cycle sends the cycle greater than described HELLO message, less than described preset working DRMaster HELLO message receiving cycle, the described default DR Master HELLO message receiving cycle of reaching the standard grade sends the cycle less than described HELLO message.

Preferably, described router also comprises:

Computing module is used for calculating by hash function the cryptographic Hash of described router self;

Comparison module electrically connects with described computing module, and the cryptographic Hash that is used for described router self that described computing module is calculated compares with other the described cryptographic Hash of leading with DR, described standby DR and described work DR;

The described module that is provided with electrically connects with described comparison module, is used for the comparative result according to described comparison module, and the multicast source of the described router and the described shared network segment or the corresponding relation of multicast group are set.

Compared with prior art, the present invention has the following advantages:

By the present invention, solved the problem that only has a multicast DR on the shared network, make to share on the network segment many routers and can both give full play to the effect of oneself, realized the whole network load balancing of multicast service, and the multicast disposal ability that has expanded the shared network segment, make the multicast processing specification of sharing on the network segment be improved.

Description of drawings

Fig. 1 is the multicast network structural representation of prior art;

Fig. 2 is the schematic flow sheet of building process of the RPT of prior art;

Fig. 3 is the schematic flow sheet of the multicast source of prior art to the process of RP registration;

Fig. 4 is the structural representation of the enterprise network multicast application networking of prior art;

Fig. 5 is a kind of schematic flow sheet of realizing the router state management method of multicast service sharing provided by the invention;

Fig. 6 is the formation schematic diagram of a kind of HELLO message provided by the invention;

Fig. 7 is the structural representation of a kind of router provided by the invention.

Embodiment

In order to solve the problems of the prior art, the present invention proposes a kind of a plurality of routers that will share on the network segment and be defined as DR, and corresponding identity state is set, make a plurality of DR finish the method for multicast functionality jointly.

In this technical scheme; the problem that need to solve have comprise following some, for convenience of description, specifically be that example is carried out corresponding description with PIM-SM; concrete technological thought still remains unchanged under other situations such as PIM-DM, and such variation does not influence protection scope of the present invention:

One, share on the network segment, all-router all needs to know have how many routers in the current shared network segment.

Two, on the current shared network segment, require to share out the work and help one another between each router.In this process, need clear and definite every router to be which multicast group service, after certain router lost efficacy simultaneously, remaining router need be finished the DR function of inefficacy router.

Three, the work of the DR of multicast source is to register to RP for (S, G), treatment principle according to prior art, that DR on the same network segment is responsible for is all on this network segment (S, registration G), and in technical scheme of the present invention, there are a plurality of DR to be the (S on this network segment, G) registration, so, these a plurality of DR will observe same rule, (S G) can only uniquely be mapped to a DR to guarantee one.Equally, recipient's side DR is responsible for that (* G) to RP registration, sets up its RPT tree, and finishes the switching of RPT to SPT, and in technical scheme of the present invention, DR also needs to observe same rule, and (* G) uniquely is mapped to one above the DR to of making.

On the basis of prior art system, the present invention has solved top three problems by the concrete technical scheme of following explanation, and a plurality of DR are set on the same network segment simultaneously, has realized the load balancing and the processing of multicast service.

It is pointed out that above-mentioned a plurality of DR that are provided with, specifically be meant to enable to share the multicast functionality that is in the router of opening on the network segment, make each router have the ability that to bear multicast service.

As shown in Figure 5, a kind of schematic flow sheet of realizing the router state management method of multicast service sharing for the present invention's proposition, this method is applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, in above-mentioned a plurality of router that is confirmed as DR router setting from as main with DR (Master DR), another router setting is from as standby DR (Backup

DR), remaining whole router settings are certainly as work DR (Active DR), and the master shares the multicast service of sharing in the network segment jointly with DR, standby DR and the DR that respectively works.

In above-mentioned scheme, DR above the shared network segment is divided into three types: main with DR, standby DR and work DR, the DR that these three kinds of roles are provided with bears the function of DR in the prior art jointly, wherein, Master DR, Backup DR, Active DR be the function of bearing network DR of equality, multicast data forwarding, in addition, interim role when also having a kind of DR of reaching the standard grade (Online DR) to be the equipment access network is provided with, and does not bear the DR function, does not promptly realize the forwarding of multicast packet.

In the shared network segment that exists above-mentioned role to be provided with, Master DR needs the state of other DR on the additional maintenance network, and on the current shared network segment issue DR identity information, simultaneously, in case Master DR lost efficacy, Backup DR will become Master DR rapidly, and send the HELLO message to other DR that share on the network segment with the identity of Master DR, after other DR receive the HELLO message of Master DR, the DR table of preserving with oneself compares, if change, then reselects (S into correspondence according to default rule and up-to-date identity setting, G) and (*, G) service.

The idiographic flow of the technical program is described as follows:

Step S501, standby DR or work DR send the cycle according to default HELLO message respectively, and the router that all in sharing the network segment are confirmed as DR sends the HELLO message, and this HELLO message comprises the current identity state information of standby DR or work DR.

The effect of this step is, in the shared network segment all are confirmed as the router of DR can inform the router that is confirmed as DR to other with the current identity state information of self by sending the HELLO message, simultaneously, also can be by receiving the HELLO message that other routers that are confirmed as DR send, know the current identity state information of other routers, especially for the main DR that uses that shares in the network segment, can be by obtaining current standby DR and the current identity state information of work DR, and, each router of sharing in the network segment is carried out condition managing in conjunction with the DR election strategy.

It is pointed out that before this step is carried out also need to carry out the DR election flow process, the specific implementation process of this flow process is as follows:

The router of sharing in the network segment that respectively is confirmed as DR sends the cycle according to default HELLO message respectively, the router transmission that in sharing the network segment all are confirmed as DR comprises the HELLO message of electing parameter, election parameter wherein comprises the IP address information at least, and optionally comprises priority parameters.

When the election parameter that is comprised in the HELLO message that router sent that respectively is confirmed as DR is priority parameters, the router that respectively is confirmed as DR compares the priority parameters of self and other priority parameters that are confirmed as the router of DR that receive by the HELLO message, if the priority of the priority parameters of self is for the highest, then be provided with from using DR as the master; If the priority of the priority parameters of self is inferior high, then be provided with certainly as standby DR; If the priority of the priority parameters of self is not the highest or inferior high, then be provided with certainly as work DR;

When having at least one to be not priority parameters in the election parameter that is comprised in the HELLO message that router sent that respectively is confirmed as DR, the router that respectively is confirmed as DR compares information of self IP address and other IP address informations that are confirmed as the router of DR that receive by the HELLO message, if its own IP address maximum then is provided with from using DR as the master; If its own IP address is inferior big, then be provided with certainly as standby DR; If its own IP address is not maximum or inferior big, then be provided with certainly as work DR.

Above-mentioned election strategy and existing DR election strategy are similar, difference is that final election results in the above-mentioned DR election strategy have distinguished the identity state of each DR, comprise main DR, standby DR and three kinds of identity states of work DR used, existing DR election strategy then only is a kind of DR of election.

Master DR election rule remains unchanged according to present PIM agreement, conducts an election according to the election parameter, and optimum DR becomes Master DR, and the DR of suboptimum becomes Backup DR, and remaining all is Active DR.

On the other hand; in concrete application scenarios; share and to have the router of not supporting multiple identity state setting (being that the multiple interfaces role is provided with) in the network segment; in this case; if according to default DR election strategy; when sharing in the network segment election parameter of not supporting the router that is confirmed as DR of many identity state configuration and being better than in this shared network segment other and being confirmed as the router of DR; this does not support the router that is confirmed as DR of many identity state configuration to bear the multicast service in this shared network segment alone; and other the router that is confirmed as DR is no longer shared multicast service; but; in concrete application scenarios; the router that is confirmed as DR of above-mentioned other may have the DR identity and the DR identity is distinguished; may no longer carry out identity yet and distinguish, such variation does not influence protection scope of the present invention.

Step S502, main with the HELLO message of DR according to standby DR or work DR transmission, obtain the current identity state information of standby DR or work DR, send the cycle according to the HELLO message, the router that in sharing the network segment all are confirmed as DR sends Master HELLO message, comprises in the Master HELLO message according to all are confirmed as the up-to-date identity state information of the router of DR in the definite shared network segment of DR election strategy.

Wherein, in the Master HELLO message,, also comprise following information except all are confirmed as the up-to-date identity state information of the router of DR in the above-mentioned shared network segment:

Share the router quantity that is confirmed as DR in the network segment;

All are confirmed as the identification information of the router of DR in the shared network segment;

Whether the router that respectively is confirmed as DR in the shared network segment supports the sign of many identity state configuration.

For above-mentioned steps, all routers that is confirmed as DR all will be monitored the HELLO message on this shared network segment on the shared network segment, write down the DR identity state of neighbours on this shared network segment, and set up the information that a database keeps each DR.DR finds and sets up neighborhood by the HELLO message.After one three layer interface enables the DR function, will periodically send the HELLO message with the multicast form, for example, purpose IP is 224.0.0.13, the transmission cycle of HELLO message is 30 seconds.In the HELLO message, can carry some parameters that the both sides neighbours consult, wherein except the parameter of HELLO HOLD TIME be must comprise, other all are optional, when the router that is confirmed as DR is received self nonrecognition or unsupported parameter, can directly skip, not influence the foundation of neighborhood like this.

At present, the parameter type that has defined has:

1 HELLO?Hold?Time

2 LAN?Prune?Delay

19 DR?Priority(PIM-SM?Only)

20 Generation?ID

21 State?Refresh?Capable(PIM-DM?Only)

22 Bidir?Capable(Bidir-PIM?Only)

24 Address?List(PIM-SM?Only)

On this basis, the present invention expands the Option capable field of PIM HELLO message, makes in the HELLO message, can carry all neighbor informations and role thereof.

The technical program expands (ALL DR) field that Option Type equals 30; the interface that shows this equipment is an interface of supporting a plurality of DR roles; wherein; 30 are the parameter type numbering; ALL DR is the title of parameter type, and in concrete the application, numbering and title all can be adjusted as required; reaching the concrete numbering made on the basis of identical technique effect and the variation of title, do not influence protection scope of the present invention.

Further, make an explanation as follows for the partial parameters item in the above-mentioned parameter type:

Option Length takies two bytes, shows the number of sharing neighbours on the network segment.

Option Value comprises all neighbours and describes, and neighbours describe totally 6 bytes, and preceding 4 bytes are IP addresses of operation PIM neighbours interface, its role of 2 explanations in back.Role definition is four kinds: Master, Backup, Active, Online; Can use 0X01,0X02,0X03,0X04 to replace respectively, the concrete parameter of representative capacity setting wherein can change according to actual needs, and such variation does not influence protection scope of the present invention.

Option Value, its form comprises: interface IP address and identify label.

Step S503, standby DR and work DR receive the main Master HELLO message that sends with DR, and according to the up-to-date identity state information in this Master HELLO message the identity state of self are set.

Concrete processing policy is as follows:

When standby DR did not receive the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, standby DR was provided with from as the main DR that uses;

When standby DR receives the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, and when the up-to-date identity state information of the standby DR that is comprised in the Master HELLO message was work DR, standby DR was provided with certainly as work DR;

When work DR did not receive the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, work DR was provided with from as the main DR that uses;

When work DR receives the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, and when the up-to-date identity state information of the work DR that is comprised in the Master HELLO message was standby DR, work DR was provided with from as standby DR;

Wherein, default standby DR Master HELLO message receiving cycle sends the cycle greater than the HELLO message, less than preset working DR Master HELLO message receiving cycle.

Moreover, after above-mentioned identity state setting is finished, when the network segment is shared in new router adding, also comprise following handling process:

The current identity state information that new router is provided with self is the DR that reaches the standard grade;

The router that DR all in the network segment of reaching the standard grade are confirmed as DR sends current identity state information that comprises self and the HELLO message of electing parameter;

Main receiving with DR after current identity state information that comprises the DR that reaches the standard grade and the HELLO message of electing parameter sends the Master HELLO message that comprises according to the up-to-date identity state information of the definite DR that reaches the standard grade of DR election strategy and election parameter to the DR that reaches the standard grade;

The DR that reaches the standard grade is provided with self identity state according to the up-to-date identity state information in the Master HELLO message, specifically comprises following several situation:

When the DR that reaches the standard grade did not receive the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade, the DR that reaches the standard grade was provided with from as the main DR that uses;

DR receives the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade when reaching the standard grade, and when the up-to-date identity state information of the DR that reaches the standard grade that is comprised in the Master HELLO message was standby DR or work DR, the DR that reaches the standard grade was provided with certainly as standby DR or work DR;

Wherein, the default DR Master HELLO message receiving cycle of reaching the standard grade sends the cycle less than the HELLO message, and such being provided with can make the DR that reaches the standard grade whether have Master DR in the shared network segment of identification rapidly.

Add sharing the network segment with new equipment A, to be that example describes as follows:

New equipment A begins to insert processing procedure when sharing the network segment, in the HELLO message of transmission, shows it oneself is Online role;

If Master DR has been arranged on the network segment, Master DR then responds a HELLO message immediately, tell the situation of DR in the present net end, after device A is received the message of Master DR, the state of oneself is modified to a kind of among Master, Backup, the Active according to election regulation, and responds the HELLO message.The DR role who carries in the message of each equipment according to Master carries out load balancing again and handles;

If there is not Master DR on the network segment, oneself becomes Master DR behind the 3s excessively, and safeguard the issue of DR information on its network segment

What need further specify is, the router of not supporting many identity state configuration that is proposed among the corresponding above-mentioned steps S501 has the situation of optimum election parameter, and changing also can appear in the processing policy of initiate router, specifies as follows:

Reaching the standard grade, to send the handling process of HELLO message constant for the router that strategy and in sharing the network segment all are confirmed as DR self set of DR, but, in follow-up flow process, owing to share and do not have the main DR that uses in the network segment, so, all routers that are confirmed as DR that receive this HELLO message all need to reply a HELLO message to this DR that reaches the standard grade, and in this HELLO message, carry self election parameter, the DR that reaches the standard grade conducts an election according to all the election parameters and the default DR election strategy that receive, and is provided with according to the identity state of election results to self.

Wherein, if election results are the election parameter optimums of DR of reaching the standard grade, and this DR that reaches the standard grade supports many identity state configuration, and then this DR that reaches the standard grade directly is provided with from using DR as main, and other DR in this shared network segment are carried out condition managing.

Enforcement scene in conjunction with concrete is specifically described above-mentioned strategy, and the state processing process of the DR of each identity setting is summarized as follows:

Online?DR：

(1) do not receive the HELLO message that Master DR sends.

If do not receive the HELLO message that Master DR sends after 3 seconds, then be provided with certainly as Master DR state.

(2) receive the HELLO message that Master DR sends.

If it is Active DR state that the HELLO message of being received is specified it, then be provided with from as the ActiveDR state, be Backup DR state if the HELLO message of being received is specified it, be provided with certainly as Backup DR state.

Active?DR：

(1) do not receive the HELLO message that Master DR sends.

If in 4 HELLO message receiving cycles, do not receive the HELLO message that Master DR sends, then be provided with certainly as Master DR state.

(2) receive the HELLO message that Master DR sends.

If it is Backup DR state that the HELLO message of being received is specified it, be provided with certainly as the BackupDR state.

Backup?DR：

(1) do not receive the HELLO message that Master DR sends.

If in 2 HELLO message receiving cycles, do not receive the HELLO message that Master DR sends, then be provided with certainly as Master DR state.

(2) receive the HELLO message that Master DR sends.

If it is Active DR state that the HELLO message of being received is specified it, be provided with certainly as Active DR state.

Master?DR：

Be higher than the HELLO message that other DR of self priority send if receive priority, elect up-to-date Master DR according to Master DR election rule after, self be set to Backup DR.

Be provided with by above-mentioned role, after Master DR lost efficacy, Backup DR perceived at first, it becomes the Master message, if Master DR and Backup DR lost efficacy simultaneously, Active DR also can perceive the inefficacy of Master DR, and it becomes Master DR.

Again on the one hand, in technical scheme of the present invention, all DR will observe same rule, guarantee identical (S, G) or (* G) is mapped to above the same DR.This rule will make mapping as much as possible evenly get final product.

Can know that by above-mentioned explanation the DR of a plurality of services is arranged in the network, how so much DR bear the role of an one DR jointly so, and this just needs a unified rule, and this case suggestion is used and shone upon similarly rule of RP among the PIM, and is specific as follows:

The router that respectively is confirmed as DR in the network will be gathered the information that provides according to DR, and using identical rule is that particular multicast group and multicast source are selected corresponding DR from numerous DR, and concrete rule is as follows:

Use the cryptographic Hash of each DR of Hash (Hash) function calculation, and the DR of selection cryptographic Hash maximum is particular multicast group and the pairing DR of multicast source.

If there are a plurality of DR to have maximum cryptographic Hash simultaneously, the DR that then selects wherein to have maximum DR address is particular multicast group and the pairing DR of multicast source.

The expression formula of hash function is: and Value (G, S, DRi)=(1103515245* ((1103515245* (G ﹠amp; S)+12345 mod 231) XOR DRi)+12345), wherein, the concrete implication of each symbol is as follows.

Each symbol implication in the hash function in the formula

Value: cryptographic Hash

The address of G:P multicast group

S: multicast source address, if be that (*, G), S then is 255.255.255.255

The IP address of DRi:DR

﹠amp; : logical operator, expression and computing

XOR: logical operator, expression XOR

Mod: arithmetic operator, the expression divide exactly get surplus

Need further be pointed out that, above-mentioned cryptographic Hash algorithm is to be that element calculates the uncommon value of Hash with source address, group address, DR address, this is a preferred embodiment of the present invention, in concrete application scenarios, can use other cryptographic Hash algorithm according to actual needs, provide the selection foundation for selecting particular multicast group and the pairing DR of multicast source among a plurality of DR in shared network.Such variation does not influence protection scope of the present invention.

By technical scheme proposed by the invention, solved the problem that only has a multicast DR on the shared network, make to share on the network segment many routers and can both give full play to the effect of oneself, realized the whole network load balancing of multicast service, and the multicast disposal ability that has expanded the shared network segment, make the multicast processing specification of sharing on the network segment be improved.

In order to realize technical scheme proposed by the invention, the present invention has further proposed a kind of router, be applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, the whole of remainder are confirmed as the router setting of DR certainly as work DR, router setting in the shared network segment of new adding is certainly as the DR that reaches the standard grade, the described main DR that uses, described standby DR and described work DR share the multicast service of sharing in the network segment jointly, and its structure chart comprises as shown in Figure 7:

Message sending module 71, when the current identity state information of this router is standby DR, work DR or when reaching the standard grade DR, be used for sending the cycle according to default HELLO message, all-router in sharing the network segment sends the HELLO message that comprises self identity state information, when the current identity state information of this router is main when using DR, be used for sending the cycle according to default HELLO message, the router that all in sharing the network segment are confirmed as DR sends the Master HELLO message of the up-to-date identity state information that comprises in the network segment of determining according to the DR election strategy all routers that are confirmed as DR;

Message receiver module 72, be used for receiving the HELLO message that other routers that are confirmed as DR of sharing the network segment send, when the current identity state information of this router is standby DR, the DR or when reaching the standard grade DR of working, also be used for receiving the Master HELLO message that the master that shares the network segment sends with DR;

Module 73 is set, electrically connect with message receiver module 72 and message sending module 71 respectively, when router is current when the identity state of self is not set, be used for the identity state that HELLO message that other routers that are confirmed as DR of the shared network segment that receives according to message receiver module 71 send and default DR election strategies are provided with self, when the current identity state information of this router is standby DR, work DR or when reaching the standard grade DR, the up-to-date identity state information that also is used for the Master HELLO message that received according to message receiver module 72 is provided with the identity state of self.

In concrete application scenarios, this router also comprises message detection module 74 and timing module 75:

Message detection module 74, with message receiver module 72 with module 73 is set electrically connects, when the current identity state information of this router is standby DR or work DR, be used for judging whether message receiver module 72 receives the main Master HELLO message that sends with DR at default standby DR Master HELLO message receiving cycle or work DR Master HELLO message receiving cycle.

Timing module 75, electrically connect with message detection module 74, be used for the HELLO message is sent the cycle, and/or default standby DR Master HELLO message receiving cycle, and/or preset working DRMaster HELLO message receiving cycle, and/or the default DR Master HELLO message receiving cycle of reaching the standard grade carries out timing.

In the case, when the current identity state information of this router is standby DR, DR or when reaching the standard grade DR works, module 73 is set also is used for testing result, the identity state that up-to-date identity state information in the Master HELLO message that is received according to the message receiver module and following strategy are provided with self according to the message detection module:

(1) situation that is standby DR for the current identity state information of this router, processing policy is as follows:

When this router did not receive the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, this router setting was from as the main DR that uses;

When this router receives the main Master HELLO message that sends with DR in default standby DR Master HELLO message receiving cycle, and when the up-to-date identity state information of the standby DR that is comprised in the Master HELLO message was work DR, this router setting was certainly as work DR;

(2) situation that is work DR for the current identity state information of this router, processing policy is as follows:

When this router did not receive the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, this router setting was from as the main DR that uses;

When this router receives the main Master HELLO message that sends with DR in preset working DR Master HELLO message receiving cycle, and when the up-to-date identity state information of this router that is comprised in the Master HELLO message was standby DR, this router setting was from as standby DR;

(3) if this router is that the current identity state information that this router is provided with self is the DR that reaches the standard grade when newly adding the router of sharing the network segment, further processing policy is as follows:

When this router did not receive the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade, this router setting was from as the main DR that uses;

When this router receives the main Master HELLO message that sends with DR in the default DR Master HELLO message receiving cycle of reaching the standard grade, and when the up-to-date identity state information of this router that is comprised in the Master HELLO message was standby DR or work DR, this router setting was certainly as standby DR or work DR;

Wherein, default standby DR Master HELLO message receiving cycle sends the cycle greater than the HELLO message, less than preset working DR Master HELLO message receiving cycle, the default DRMaster HELLO message receiving cycle of reaching the standard grade sends the cycle less than the HELLO message.

In concrete application scenarios, this router also comprises:

Computing module 76 is used for calculating by hash function the cryptographic Hash of this router self;

Comparison module 77 electrically connects with computing module 76, and the cryptographic Hash that is used for router self that computing module 76 is calculated compares with other main cryptographic Hash with DR, standby DR and the DR that works;

Module 73 is set, electrically connects, be used for comparative result, the multicast source of this router and the shared network segment or the corresponding relation of multicast group are set according to comparison module 78 with comparison module 77.

Through the above description of the embodiments, those skilled in the art can be well understood to the present invention and can realize by hardware, also can realize by the mode that software adds necessary general hardware platform.Based on such understanding, technical scheme of the present invention can embody with the form of software product, it (can be CD-ROM that this software product can be stored in a non-volatile memory medium, USB flash disk, portable hard drive etc.) in, comprise some instructions with so that computer equipment (can be personal computer, server, the perhaps network equipment etc.) each implements the described method of scene to carry out the present invention.

It will be appreciated by those skilled in the art that accompanying drawing is a preferred schematic diagram of implementing scene, module in the accompanying drawing or flow process might not be that enforcement the present invention is necessary.

It will be appreciated by those skilled in the art that the module in the device of implementing in the scene can be distributed in the device of implementing scene according to implementing scene description, also can carry out respective change and be arranged in the one or more devices that are different from this enforcement scene.The module of above-mentioned enforcement scene can be merged into a module, also can further split into a plurality of submodules.

The invention described above sequence number is not represented the quality of implementing scene just to description.

More than disclosed only be several concrete enforcement scene of the present invention, still, the present invention is not limited thereto, any those skilled in the art can think variation all should fall into protection scope of the present invention.

Claims

1, a kind of method of state management of realizing multicast service sharing between the Designated Router DR, it is characterized in that, be applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, remaining whole router settings are certainly as work DR, the described main DR that uses, described standby DR and described work DR share multicast service in the described shared network segment jointly according to the strategy of load balancing, and described method specifically comprises:

2, the method for claim 1, it is characterized in that, the DR election strategy that described basis is default, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, remaining whole router settings as work DR, are specially certainly:

3, method as claimed in claim 2, it is characterized in that, when the default DR election strategy of basis, when election parameter of not supporting the router of many identity state configuration was better than other routers in the described shared network segment in the router of described a plurality of DR of being confirmed as, the described router of not supporting many identity state configuration was born the multicast service in the described shared network segment.

As claim 1 or 3 described methods, it is characterized in that 4, described Master HELLO message also comprises:

DR quantity in the described shared network segment;

5, the method for claim 1, it is characterized in that, described standby DR and described work DR receive the Master HELLO message that described master sends with DR, and according to the up-to-date identity state information in the described Master HELLO message self identity state are set, and are specially:

Wherein, described default standby DR Master HELLO message receiving cycle sends the cycle greater than described HELLO message, less than described preset working DR Master HELLO message receiving cycle.

6, method as claimed in claim 1 or 2 is characterized in that, when new router added the described shared network segment, described method also comprised:

7, method as claimed in claim 3 is characterized in that, when new router added the described shared network segment, described method also comprised:

8, method as claimed in claim 6 is characterized in that, the described DR of reaching the standard grade is provided with self identity state according to the up-to-date identity state information in the described MasterHELLO message, is specially:

9, the method for claim 1 is characterized in that, describedly main shares multicast service in the described shared network segment jointly with DR, described standby DR and described work DR, is specially:

10, a kind of router, it is characterized in that, be applied to comprise in the shared network segment of router of a plurality of DR of being confirmed as, wherein, according to default DR election strategy, a router setting is from using DR as the master in the router of described a plurality of DR of being confirmed as, another router setting is certainly as standby DR, remaining whole router settings are certainly as work DR, router setting in the described shared network segment of new adding is certainly as the DR that reaches the standard grade, describedly main share multicast service in the described shared network segment jointly, comprising with DR, described standby DR and described work DR:

11, router as claimed in claim 10 is characterized in that, also comprises message detection module and timing module:

In this case:

Wherein, described default standby DR Master HELLO message receiving cycle sends the cycle greater than described HELLO message, less than described preset working DRMaster HELLO message receiving cycle, the described default DRMaster HELLO message receiving cycle of reaching the standard grade sends the cycle less than described HELLO message.

12, router as claimed in claim 10 is characterized in that, also comprises: