CN102984074B - Based on the multicast routing optimization method that many Upstream Interface IGMP/MLD acts on behalf of - Google Patents

Abstract

The invention discloses a kind of multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD, comprise the following steps: described many Upstream Interface IGMP/MLD agency has multiple Upstream Interface; For transmission multicast address be the multicast source of (S, G), its Upstream Interface used has and only has one; For the multicast receivers that receiving group address is (S, G) or (*, G), its Upstream Interface used has and only has one; The Upstream Interface that multicast source or multicast receivers are using is called actual Upstream Interface; Default upstream interface is called according to the operable Upstream Interface that routing table and policybased routing are selected; * any multicast source comprising S is represented.Present invention efficiently solves tunnel to converge problem, improve mobile multicast router efficiency and realize performance optimization.

Description

Based on the multicast routing optimization method that many Upstream Interface IGMP/MLD acts on behalf of

Technical field

The present invention relates to QoS routing.More specifically, the present invention relates to a kind of multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD.

Background technology

Shown in the abbreviation used in this specification and technical term are defined as follows:

IETF:InternetEngineeringTaskForce, internet engineering duty group;

Multimob:MulticastMobility, mobile multicast working group;

IGMP:InternetGroupManagementProtocol, Internet Group Management Protocol;

MLD:MulticastListenerDiscovery, multicast listener finds;

MIPv6:MobileIPv6, mobile IP v 6;

HMIPv6:HierarchicalMobileIPv6, hierarchy motion Ipv 6;

PMIPv6:ProxyMobileIPv6, proxy mobile IPv 6;

IGMP/MLDProxying:IGMP/MLD acts on behalf of;

DR:DesignatedRouter, Designated Router;

MTMA:MulticastTreeMobilityAnchor, multicast tree mobile anchor point;

MN:MobileNode, mobile node;

HA:HomeAgent, home agent;

FA:ForeignAgent, Foreign Agent;

MAP:MobilityAnchorPoint, mobile anchor point;

LMA:LocalMobilityAnchor, local mobile anchor;

MAG:MobilityAccessGateway, Mobile Access Gateway;

MR:MulticastRouter, multicast router.

Multicasting technology is a kind of data dissemination mode between clean culture and broadcast.Compare with broadcast mode with traditional clean culture, multicasting technology can solve single point-to-multipoint data transmission issues more effectively, saves the network bandwidth, reduces offered load, improves data transmission efficiency.But only for stationary nodes at the beginning of multicast design, do not consider the mobility problem of interdependent node.Along with the proposition in succession of a series of mobility management protocol such as MIPv6, HMIPv6, PMIPv6, how the appearance in succession of large discharge, high quality-of-service Network, be combined one of study hotspot becoming present stage by multicasting technology with mobility management protocol.Because mobility management protocol is mostly mode of unicast design, simply it is combined with multicast protocol and can not reach ideal effect.

IETFMultimob working group is devoted to study the mobile multicast solution based on PMIPv6, an existing RFC2 section, Working Group Draft 3 sections and 9 sections, individual draft in recent years.ThomasC.Schmidt etc. proposed and moved basic multicast based on the recipient under PMIPv6 framework and support scheme in April, 2011.This draft adopts IGMP/MLD agency agreement to support multicast functionality, and Multimob working group is in this, as the initial development direction of this working group and basic deployment scheme.

IGMP/MLD agency agreement is integration to multicast protocol and IGMP/MLD agreement and optimization.It should realize, to the management of the multicast source/multicast receivers be on its downstream interface, being equivalent to the function of DR in multicast protocol; On Upstream Interface, serve as recipient again, the recipient representing its downstream interface sets up multicast transmit tree, receiving multicast data.

IGMP/MLD agency agreement is applicable in simple tree structure, and the router running IGMP/MLD agency agreement need not rerun multicast protocol.Specify in agreement, the router running IGMP/MLD agency agreement can only configure a Upstream Interface and one or more downstream interface.Upstream Interface points to more wide multicast domain, namely Upstream Interface must be connected to the router that is run multicast protocol or IGMP/MLD agency agreement, downstream interface can point to the router running IGMP/MLD agency agreement, also directly can point to multicast receivers.But because IGMP/MLD agency is only for stationary nodes, its application scenarios is simple tree structure, only allow a Upstream Interface as pointing to the interface of multicast domain, this is that multicast groups in other application scenarioss especially in mobile environment brings inconvenience.In addition, if this unique Upstream Interface breaks down, all recipients of its downstream interface all can not receive multicast packet, and robustness is poor.

The technical scheme of the first prior art: ThomasC.Schmidt etc. propose based on the mobile multicast scheme under PMIPv6 framework.Design due to PMIPv6 is the transmission means for clean culture, and after MAG receives multicast packet, self not corresponding multicast forwarding rule, finally can only discard these multicast packets.This scheme, by the multicast forwarding function realizing MAG MAG deploy IGMP/MLD agency, makes PMIPv6 agreement possess multicast forwarding function.Concrete mechanism is as follows:

The program is by acting on behalf of at LMA deploy multicast protocol, MAG deploy IGMP/MLD, if its Upstream Interface is that MAG-LMA tunnel interface is to realize the transmission of multicast packet in PMIPv6 territory.Because an IGMP/MLD agent entity has only allowed a Upstream Interface, so each MAG-LMA tunnel interface can only be used by an IGMP/MLD agent entity, this agent entity contains all MN of this specific LMA of all sensings.Multiple MN is belonged to the situation of Different L MA, MAG is upper can only dispose multiple IGMP/MLD agent entity according to the number of LMA.In multicast packet transport process, MAG can according to the consensus standard of IGMP/MLD agency, integrate the multicast group subscription information that access belongs to all MN of current I GMP/MLD agent entity under this MAG, and represent the tunnel interface transmission multicast report message of these MN by corresponding MAG-LMA.Can multicast tree be added after LMA receives these information, thus obtain multicast packet, and then forward to MAG.MAG forwards to the MN of each access under it again, completes the function of multicast data forwarding.

The shortcoming of technique scheme is:

The program adopts bidirectional tunneling mode, there is the comparatively large problem do not optimized with the such as route such as Triangle routing, tunnel convergence of overhead of data.And, because IGMP/MLD agency has only allowed a Upstream Interface, for belonging to the MN of Different L MA under being linked into same MAG, MAG needing run multiple IGMP/MLD and acting on behalf of, this just causes MAG to receive confusion and the tunnel convergence problem of data, as shown in Figure 1.MN1, MN2 set up binding relationship with LMA1 and LMA2 respectively, and request adds identical multicast group.The IGMP/MLD report message that now group address is identical can send from the Upstream Interface of two IGMP/MLD agent entitys, the LMA belonging to arriving separately respectively through tunnel Tun1 and tunnel Tun2.After LMA1 and LMA2 receives multicast packet, then be forwarded to MAG through Tun1 and Tun2 simultaneously, now on MAG by receiving two parts of identical multicast packets, cause data redundancy.

The technical scheme of the second prior art: after RFC6224 issues, Multimob issues Working Group Draft ROPT.This draft proposes two kinds of solutions for the tunnel problem that converges.

First method is by setting up special multicast tree mobile anchor point MTMA, transmitting multicast packet while alleviating LMA load in PMIPv6 territory.MAG disposes IGMP/MLD agency equally, and Upstream Interface points to MTMA and is no longer LMA.MAG converge these information, and its lower MN transmission of representative access adds multicast report message to MTMA after receiving the multi-cast subscriptions information that MN sends.After MTMA receives this convergence message, add multicast tree and multicast data forwarding to MN.

Another kind method is that MAG is directly connected with a multicast router MR, and MAG runs IGMP/MLD agency and Upstream Interface is set to the interface direct-connected with MR.MAG after receiving the multi-cast subscriptions information that MN sends converges these message, and its lower MN transmission of representative access adds multicast group report message to MR.MR adds multicast tree and obtains multicast packet and forward to MN.Multicast packet is without the need to passing through the tunnel transmission of MTMA or LMA, the expense caused when decreasing encapsulation tunnel.

The shortcoming of the second existent technique scheme is:

First, for the first method of the program, author does not indicate the matching method that tunnel uses.If MN and MTMA mates, its operation principle is similar to PMIPv6, can produce the problem etc. that tunnel converges problem, MTMA overload equally.If MAG and MTMA mates, converge problem in order to avoid tunnel, MAG can be connected from multiple MTMA being in charge of different multicast group or MAG is fixing is connected with certain MTMA.For the method by multicast group classification, now, MAG is upper can be run multiple IGMP/MLD and act on behalf of, and can cause the confusion of data receiver, forwarding; And MAG is fixed to the method be connected with certain MTMA, then there is serious single point failure problem.3rd, no matter which kind of matching way tunnel uses, MTMA and MAG needs binding information extra alternately, for link brings extra consumption burden.

In addition, second method can cause larger handoff delay.Because IGMP/MLD acts on behalf of the uniqueness of Upstream Interface, each MAG can only connect a MR, and the MR after switching needs to re-establish multicast transmit tree after receiving multicast group subscribe message, and the multicast tree that original MR sets up is discarded completely.When the program causes each MN to switch, all need to re-establish multicast transmit tree, thus cause larger handoff delay.

To sum up, traditional IGMP/MLD agency only has a Upstream Interface, cause in (as MIPv6, HMIPv6 etc.) and other multicast application scenes, needing to meet at the mobile entities such as such as MAG, FA, MAP or related multicast application entity deploy multiple IGMP/MLD agent entity the cast communication requirement being subordinate to the MN of different multicast agent (as LMA, HA or other related proxy entities etc.) in above-mentioned and similar mobile environment scene.But because the application scenarios of IGMP/MLD agency is simple tree structure, its upstream link generally only has one, therefore, for the topological structure of such as Fig. 1, under upstream link has multiple scenes, common IGMP/MLD agency has some limitations, and can not well be suitable for, and causes tunnel to converge problem.

Summary of the invention

The object of the invention is to provide a kind of multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD, avoids the route redundancy problems such as tunnel convergence.

Concrete technical scheme is as follows:

The multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD comprises the following steps:

Described many Upstream Interface IGMP/MLD agency has multiple Upstream Interface;

For transmission multicast address be the multicast source of (S, G), its Upstream Interface used has and only has one; For the multicast receivers that receiving group address is (S, G) or (*, G), its Upstream Interface used has and only has one; The Upstream Interface that multicast source or multicast receivers are using is called actual Upstream Interface; Default upstream interface is called according to the operable Upstream Interface that routing table and policybased routing are selected; * any multicast source comprising S is represented.

For the multicast group (S, G) that recipient subscribes to, described many Upstream Interface IGMP/MLD acts on behalf of the IGMP/MLD message information without the need to forwarding to its Upstream Interface about (S, G).

The group membership of described multicast group comprises mobile node.

Further, the method comprises the following steps:

S1, when mobile node access downstream links, trigger described many Upstream Interface IGMP/MLD and act on behalf of and send general inquiry message;

After S2, described mobile node receive described general inquiry message, send the multicast group that IGMP/MLD message information adds to described this mobile node request of many Upstream Interface IGMP/MLD Agent Advertisement, and by the actual Upstream Interface of multicast group described in many Upstream Interface IGMP/MLD agent selection; Described IGMP/MLD message information is sent by mobile node and comprises the multi-cast subscriptions information of this mobile node;

After S3, described many Upstream Interface IGMP/MLD agency receives the described IGMP/MLD message information of its lower mobile node transmission of access, set up for described multicast group or upgrade multicast forward table, and periodically sending according to this multicast forward table and integrate IGMP/MLD message information to upstream link corresponding to the actual Upstream Interface of described multicast group;

The multicast packet of S4, described multicast group, by this actual Upstream Interface, is forwarded to its downstream interface according to described multicast forward table by described many Upstream Interface IGMP/MLD agency;

S5, described many Upstream Interface IGMP/MLD agency is by recording group membership's quantity of described multicast group or finding out the existence of Upstream Interface of described multicast group, dynamically upgrade the actual Upstream Interface of described multicast group, and send described integration IGMP/MLD message information by the actual Upstream Interface upgraded.

Further, described step S1 is further comprising the steps:

Described mobile node is respectively each group address start-up study timer of the multicast group that will receive, described back off timer is [0, maximum response time] between get a random number, described back off timer is to after date, and described mobile node sends IGMP/MLD message information.

Further, described step S3 is further comprising the steps:

When (S, G) exists with (*, G) simultaneously, if the actual Upstream Interface that described integration IGMP/MLD message information is corresponding is different, then (S, G) and (*, G) send respectively to respective actual Upstream Interface and integrate IGMP/MLD message information;

Wherein, (*, G) sends and comprises the integration IGMP/MLD message information of (G, Exclude, S) until (S, G) state is cancelled, and S represents the address of multicast source.

Or directly select to (*, G) actual Upstream Interface sends integrates IGMP/MLD message information, until (*, G) cancels, (S, G) could select the default upstream interface of oneself to send as actual Upstream Interface and integrate IGMP/MLD message information.

Further, described step S4 is further comprising the steps: if described many Upstream Interface IGMP/MLD acts on behalf of forward (* according to described multicast forward table to its downstream interface, or (S G), G) while multicast packet, there is the situation that multicast source S sends the multicast packet of multicast group G in its downstream interface, then described many Upstream Interface IGMP/MLD acts on behalf of the downstream interface multicast data forwarding subscribing to this multicast packet to other except downstream interface corresponding to multicast source S, also need the default upstream interface multicast data forwarding to multicast source S, and, subscribe to multicast group (*, G) corresponding actual Upstream Interface need send and comprise (G, Exclude, S) integration IGMP/MLD message information, wherein, the default upstream interface depending on described multicast source S is its actual Upstream Interface.For the multicast group (S, G) that recipient subscribes to, described many Upstream Interface IGMP/MLD acts on behalf of the IGMP/MLD message information without the need to forwarding to its Upstream Interface about (S, G).

Further, described step S5 is further comprising the steps:

Step S51, when described mobile node leaves, send the described many Upstream Interface IGMP/MLD of state variation report notice to act on behalf of, described in described many Upstream Interface IGMP/MLD agents query, whether group membership's quantity of multicast group is 0, if it is performs step S52, if not, then perform step S53

The cache entries of step S52, the directly described multicast group of deletion;

Whether step S53, the described mobile node of continuation inquiry are last group memberships that in described multicast group, actual Upstream Interface is consistent with default upstream interface, if not then performing step S54; If it is step S55 is performed;

Step S54, delete IP address entry about described mobile node;

Step S55, select new actual Upstream Interface;

Or described step S5 is further comprising the steps:

S56, when described in described many Upstream Interface IGMP/MLD delegates perceive, the actual Upstream Interface of multicast group is cancelled, whether group membership's quantity of inquiry (can send general inquiry message or ad hoc inquiry message asks) described multicast group is 0, if it is perform step S52, otherwise perform step S55.

Further, described step S55 is further comprising the steps:

Described many Upstream Interface IGMP/MLD agency selects according to multicast receivers quantity under the default upstream interface under multicast group different in multicast forward table, and the default upstream interface selecting quantity maximum is as new actual Upstream Interface;

If quantity is identical, then the preferred value pre-set according to default upstream interface, the time of existence or Stochastic choice way selection go out an actual Upstream Interface, rejoin multicast tree;

For the group membership of first multicast group, the default upstream interface of this group membership is as being actual Upstream Interface.

Further, for the entity running described many Upstream Interface IGMP/MLD agency, the interface on this entity can not become Upstream Interface and downstream interface simultaneously.

The present invention proposes a kind of more flexibly based on the multicast routing optimization method that many Upstream Interface IGMP/MLD acts on behalf of, make full use of while IGMP/MLD acts on behalf of advantage, converge problem by efficiently solving tunnel at the details of downstream interface record multicast receivers, the mode allowing multiple Upstream Interface to exist and corresponding Upstream Interface dynamic selection method, improve mobile multicast router efficiency and realize performance optimization.The program can be deployed in the more complicated non-tree network structure of such as mobile environment etc., and range of application is more wide.

Accompanying drawing explanation

Below with reference to accompanying drawings and the present invention is specifically described in conjunction with the embodiments.

Fig. 1 is that the technical scheme of the first prior art produces tunnel convergence problem schematic diagram;

Fig. 2 is the method flow diagram that many Upstream Interface IGMP/MLD agency dynamically updates actual Upstream Interface;

The deployment schematic diagram that Fig. 3 the present invention many Upstream Interface IGMP/MLD acts on behalf of;

The flow chart of Fig. 4 specific embodiment of the invention.

Embodiment

With reference to the accompanying drawings and by embodiments of the invention, technical scheme of the present invention is described in detail.

It should be noted that, in below describing, the group membership of multicast group comprises mobile node MN, and mobile node MN is the group membership of multicast group, is also the multicast receivers (representing with R) of subscription group multicast data.

In multicast mechanism, multicast forwarding forms tree structure, root is multicast source or converging information point normally, leaf normally connects the multicast router of recipient, wherein point to root in other words from multicast source or converging information point more close to interface be Upstream Interface, the interface of the router of multicast source or converging information point is exactly downstream interface dorsad.

Because the present invention acts on behalf of, so Upstream Interface, downstream interface are all for MAG at MAG deploy many Upstream Interface IGMP/MLD.Namely, under proxy-mobile IP, the MAG-LMA tunnel interface that the MAG that the LMA of Upstream Interface belonging to MN and this MN accesses sets up, also can be the interface that MAG points to multicast router; The interface of the WAP (wireless access point) (being called for short AP) that downstream interface accesses for MAG connection MN.

About IGMP/MLD message information, the IGMP/MLD message information that MN sends only represents self, and to the subscription demand of multicast packet, many Upstream Interface IGMP/MLD agency is that its lower all recipient of representative access subscribes to demand to multicast packet, the subscribe request of each MN is integrated send again, this is acted on behalf of to integrate and be called in this manual through the IGMP/MLD message information that Upstream Interface forwards by many Upstream Interface IGMP/MLD and integrates IGMP/MLD message information, if Upstream Interface points to LMA, this integration IGMP/MLD message information is just sent to LMA by MAG-LMA tunnel, if Upstream Interface points to multicast router and is just sent to multicast router.

Because IGMP/MLD agent application is in edge network, its application scenarios is simple tree structure, and its Upstream Interface is unique, and this is that multicast groups under different scene, especially under mobile environment brings many inconvenience.Many Upstream Interface IGMP/MLD agency is applied to edge network equally, its Upstream Interface, downstream interface mode of operation and IGMP/MLD act on behalf of substantially identical, Upstream Interface runs the host function specified in IGMP/MLD protocol suite, downstream interface runs the routing function specified in IGMP/MLD protocol suite, but difference is that many Upstream Interface IGMP/MLD agency has multiple Upstream Interface, this many Upstream Interface IGMP/MLD agency allows multiple Upstream Interface to exist while recording its downstream interface recipient information in detail simultaneously, but be (S for transmission multicast address, G) multicast source, its Upstream Interface used has and only has one, be (S for receiving group address, G) or the multicast receivers of (*, G), its Upstream Interface used has and only has one, to avoid redundancy and the confusion of muticast data transmission, this Upstream Interface used is called actual Upstream Interface.And under non-simple tree structure, because upstream link exists multiple, for multicast group, beyond the actual interface that removing is using, all the other operable Upstream Interface of multicast group selected according to unicast routing table, multicast routing table and policybased routing etc. are called default upstream interface.

The IGMP/MLD message information that many Upstream Interface IGMP/MLD acts on behalf of the recipient of downstream interface sends has integration and inhibitory action.For the multicast group existed, when receiving the IGMP/MLD message information of the recipient's transmission newly adding multicast group, many Upstream Interface can not be that it sends separately IGMP/MLD message information to actual Upstream Interface and default upstream interface again, but periodically send the IGMP/MLD message information after integrating to actual Upstream Interface.After actual interface lost efficacy, default interface can become actual interface.

For PMIPv6, as shown in Figure 1, MN1, MN2 set up binding relationship with LMA1 and LMA2 respectively, and request adds identical multicast group (*, G) or (S, G), then according to PMIPv6 routing policy, the default upstream interface of MN1, MN2 is the tunnel interface of MAG side, MAG-LMA1 and MAG-LMA2 tunnel respectively, and points to LMA1, LMA2 respectively.In FIG, MAG-LMA1 tunnel Tun1 represents, MAG-LMA2 tunnel Tun2 represents.

If the multi-cast subscriptions information of MN1 and MN2 mails to respective default upstream interface respectively, described tunnel will be produced and converge problem.Therefore, for this multicast group (*, or (S G), G), its Upstream Interface used has and only has one, therefore select one of them in the tunnel interface in MAG-LMA1 tunnel, MAG side or the tunnel interface in MAG-LMA2 tunnel as actual Upstream Interface, to avoid redundancy and the confusion of muticast data transmission.

Many Upstream Interface IGMP/MLD acts on behalf of Upstream Interface and runs the host function specified in IGMP/MLD protocol suite, replys multicast general inquiry message (GeneralQuery is called for short GQ) and the ad hoc inquiry message of the transmission of its upstream link.Wherein, general inquiry message periodically sends, on interrogation link, all recipients subscribe to the demand of multicast information, ad hoc inquiry message sends under special circumstances, only asking portion divides recipient to subscribe to the demand of multicast information, wherein ad hoc inquiry message is to confirm whether link also exists a multicast receivers, to improve the accuracy of inquiry.General inquiry message and ad hoc inquiry message are the mechanism of IGMP/MLD agreement regulation itself.If group membership's information of many Upstream Interface IGMP/MLD proxy caching changes, then the Upstream Interface running the MAG that this many Upstream Interface IGMP/MLD acts on behalf of needs to send group membership's state change information to its upstream link.

Recipient's quantity of many Upstream Interface IGMP/MLD proxy records multicast group, find out the existence of its Upstream Interface, dynamically for multicast receivers selects new Upstream Interface, and send IGMP/MLD message information to its upstream link.When recipient R leaves multicast group (*, or (S G), G) time (hereinafter referred to as " G "), first many Upstream Interface IGMP/MLD agency judges whether multicast group G recipient quantity is 0, directly delete multicast group G cache entries, otherwise continue to judge recipient R be whether in multicast group G actual interface consistent with default interface last member, otherwise the cache entries of deletion multicast group recipient R selects new Upstream Interface.When the Upstream Interface of the former multicast group G of many Upstream Interface IGMP/MLD delegates perceive is cancelled, whether inquiry (can send general inquiry message or ad hoc inquiry message asks) multicast group G recipient quantity is 0, is directly delete multicast group G cache entries; Otherwise directly select new Upstream Interface, as shown in Figure 2.Upstream Interface is selected to select mechanism as follows: many Upstream Interface IGMP/MLD agency selects according to multicast receivers quantity under this default interface under multicast group G, the default interface selecting quantity maximum is as new actual Upstream Interface, if quantity is identical, the way selection such as the preferred value that can pre-set according to default upstream interface, the time of existence or Stochastic choice go out an actual Upstream Interface, rejoin multicast tree, for the recipient of first subscription multicast group G, its default upstream interface is actual Upstream Interface.

Many Upstream Interface IGMP/MLD acts on behalf of downstream interface to be needed to run the routing function specified in IGMP/MLD protocol suite, difference is that each downstream interface needs to safeguard more detailed group membership's information, for a downstream interface, recipient can subscribe to multicast information by sending IGMP/MLD message, the all recipients of this downstream interface can utilize basic cache entries to represent about a subscription situation of multicast packet entirety, as shown in table 1.Each downstream interface needs to integrate and the details of its lower multicast receivers subscription multicast of buffer memory.Afterwards, many Upstream Interface IGMP/MLD acts on behalf of all downstream interface multi-cast subscriptions situations integrated as table 1, read the configuration file that default upstream interface is set, the default upstream interface of MN is found out according to IP address or prefix, and default upstream interface is consistent and the MN subscribing to same multicast group assigns to a class, because subscription information can only be gone out from a Upstream Interface, thus initiate the sequencing of multi-cast subscriptions according to MN, Upstream Interface selects mechanism to select before actual Upstream Interface is attached to.Wherein use (S, G) group to representing a multicast conversation, wherein G represents an IP multicast group, and for specific source multicasting, S represents the multicast source being sent to multicast group G, and for Any-Source Multicast, * represents any one source being sent to multicast group G.In table 1, (*, G) and (S, G) represents with the form of (Si, Gj), and i represents the numbering in source, and j represents the numbering of multicast group.For any source situation, S is then set to NULL or *.

The multi-cast subscriptions information cache entry of each downstream interface multicast receivers of table 1

Many Upstream Interface IGMP/MLD acts on behalf of the subscription information integrating each downstream interface multicast receivers, and generate transmitting and according to this table, sending the IGMP/MLD message information after integrating to the upstream link corresponding to actual Upstream Interface as table 2 according to the default upstream interface message of multicast receivers.For multicast group G, when (S, G) and (*, G) simultaneous situation, the actual Upstream Interface corresponding to IGMP/MLD message information may be different.When its actual Upstream Interface is identical, send (S, G) and (*, G) IGMP/MLD message information to upstream link simultaneously; When actual Upstream Interface is different, (S, G) with (*, G) send the IGMP/MLD message information after integrating according to the actual Upstream Interface of oneself respectively, difference is, (*, G) (G is sent, Exclude, S) IGMP/MLD message information with avoid the multicast packet of source S repeat receive until (S, G) state is cancelled; Or directly select to (*, G) actual Upstream Interface sends integrates IGMP/MLD message information, until (*, G) cancels, (S, G) could select the default upstream interface of oneself to send as actual Upstream Interface and integrate IGMP/MLD message information.

Table 2 transmitting multicast data table

The Upstream Interface acted on behalf of due to many Upstream Interface IGMP/MLD and downstream interface run the difference in functionality of IGMP/MLD agreement defined respectively, it is widely different to data, signaling information processing mode, therefore, for the entity running many Upstream Interface IGMP/MLD agency, interface on this entity can not become Upstream Interface and downstream interface simultaneously, to avoid the confusion of data transmit-receive.

It is as follows that many Upstream Interface IGMP/MLD proxy data forwards rule:

After receiving multicast packet from upstream link, many Upstream Interface IGMP/MLD acts on behalf of according to table 2 to its downstream interface multicast data forwarding; When there are multicast source S transmission multicast group G data in its downstream interface, many Upstream Interface IGMP/MLD acts on behalf of and (removes the downstream interface that source S multicast packet reaches) according to table 2 to while its downstream interface multicast data forwarding, and to the default upstream interface multicast data forwarding of source S.For multicast source, be actual Upstream Interface depending on its default upstream interface usually.In addition, for the actual Upstream Interface corresponding to (*, the G) in table 2, the IGMP/MLD message information that should send (G, Exclude, S) to upstream link with avoid the multicast packet of source S repeat receive; For the multicast group (S, G) that recipient subscribes to, described many Upstream Interface IGMP/MLD acts on behalf of without the need to forwarding about (S, G) IGMP/MLD message information to its Upstream Interface.

Set forth as an example with PMIPv6 scene, but the method is suitable for and other similar multicast application scenes such as MIPv6, HMIPv6, FMIP, DMM equally.

In the scene of PMIPv6, the default upstream interface of MN should be the tunnel interface of MAG-LMA, the corresponding LMA of each Upstream Interface that many Upstream Interface IGMP/MLD acts on behalf of, when the MN belonging to identical LMA accesses the downstream interface that many Upstream Interface IGMP/MLD acts on behalf of, select identical MAG-LMA tunnel interface as Upstream Interface.Example topology as shown in Figure 3.MN1 belongs to LMA1 management, and the default upstream interface of MN1 is the tunnel interface of MAG side, MAG-LMA1 tunnel; MN2 belongs to LMA2 management, and the default upstream interface of MN2 is the tunnel interface of MAG side, MAG-LMA2 tunnel.MN1, MN2 are multicast receivers, MN1 subscribes to the data of multicast group G1, sends the data transmission (* of (*, G1) IGMP/MLD message information, MN2 subscription multicast group G1 and G2, G1) IGMP/MLD message information and (*, G2) IGMP/MLD message information.Suppose that access order is for MN1, MN2, leave order for MN1, MN2.

Generally when MN accesses MAG, traditional MLD agency can send general inquiry message within the cycle of 125s.This time delay can cause the multicast member state of actual multicast member state and MLD proxy records asynchronous.So the present invention's regulation is once MN accesses downstream links, just triggers many Upstream Interface IGMP/MLD and act on behalf of transmission general inquiry message, send again when the cycle to be interrogated need not be waited to arrive.After MN receives query message, for each group address that will receive starts a back off timer.The value of timer gets a random number between [0, maximum response time].Timer is to after date, and MN can send report message and notice to MAG the multicast group address that MN thinks reception.Its operating process as shown in Figure 4.

1) MN1 accesses MAG, triggers many Upstream Interface IGMP/MLD and acts on behalf of transmission general inquiry message (being called for short GQ).

2) after many Upstream Interface IGMP/MLD agency receives the report message of MN1, for multicast group G sets up multicast forward table, as shown in table 3.Because MN1 adds multicast group G1 first, its default upstream interface is the actual Upstream Interface of multicast group G.

(*,G1)

1

LMA1

LMA1

1

Residing downstream interface

MN1IP address

The multicast forward table set up after table 3 more than Upstream Interface IGMP/MLD agency receives the report message of MN1

3) many Upstream Interface IGMP/MLD acts on behalf of and sends integration IGMP/MLD message to LMA1 by Upstream Interface, and the multicast packet of multicast group G1 is forwarded to MN1 through LMA1-MAG tunnel.It should be noted that: IGMP/MLD message is different with integration IGMP/MLD message, and the former source address is MN, and the latter's source address is MAG.Integrating IGMP/MLD message is gone to send by the many Upstream Interface IGMP/MLD Agent on behalf MN operated on MAG, if now MN is first IGMP/MLD message sending multicast group G, and do not have other recipients to subscribe to identical information, it is consistent with MN that many Upstream Interface IGMP/MLD acts on behalf of the IGMP/MLD message sent, because now many Upstream Interface IGMP/MLD agency only represents a MN, when multiple MN exists time, that it represents is all MN, and integrating IGMP/MLD message is the multi-cast subscriptions demand IGMP/MLD message meeting all MN.

4) MN2 accesses MAG, triggers many Upstream Interface IGMP/MLD and sends general inquiry message to MN1 and MN2.MN1 replys general inquiry message according to the back off timer of self.MN2 sends IGMP/MLD message to MAG, adds multicast group G1 and G2.IGMP/MLD agency upgrades the multicast forwarding entry of multicast group G1 after receiving the IGMP/MLD message of MN2, increases the multicast forwarding entry of multicast group G2 simultaneously, and sends IGMP/MLD message to LMA2, as shown in table 4.

Multicast forward table after table 4 more than Upstream Interface IGMP/MLD agent update

5) according to table 4, the IGMP/MLD message of G1 is still sent to LMA1 by many Upstream Interface IGMP/MLD agency, and the data of multicast group G1 are forwarded to MN1 and MN2 through LMA1-MAG tunnel; The IGMP/MLD message of G2 is sent to LMA2 by many Upstream Interface IGMP/MLD agency simultaneously, and the data of multicast group G2 are forwarded to MN2 through LMA2-MAG tunnel.

6) when MN1 leaves MAG, send state variation report (State-changeReport) to MAG, notice many Upstream Interface IGMP/MLD to act on behalf of MN1 and will leave multicast group, whether first many Upstream Interface IGMP/MLD agency inquires about MN1 in multicast forward table G1 entry is last group membership in G1 group or judges whether the group membership in G1 is 0.If so, then directly G1 entry is deleted; If not (this example is "no"), whether many Upstream Interface IGMP/MLD agency inquires about MN1 in multicast forward table G1 entry is last group membership that in G1 group, actual interface is consistent with default interface.(a) if not, then delete the IP address entry of MN1; B () is if (this example is "Yes"), MAG-LMA1 tunnel is deleted, select the actual Upstream Interface of tunnel interface as multicast group G1 of MAG-LMA2, and initiatively send IGMP/MLD message information (*, G1), rejoin multicast tree, multicast packet is forwarded to MN2 through LMA2-MAG tunnel.Cache entries such as table 5 shows.When many Upstream Interface IGMP/MLD agency does not receive the leave message of MN1 but cancelling of MAG-LMA1 tunnel detected, first judge whether group G1 recipient quantity is 0, is, deletes G1 entry; Otherwise process according to (b).

(*,G1)

1

LMA2

LMA2

1

Residing downstream interface

MN2IP address

(*,G2)

1

LMA2

LMA2

1

Residing downstream interface

MN2IP address

Table 5:IGMP/MLD agency receive MN1 leave message after group membership's state information of setting up

MN2 leaves MAG, send state variation and report MAG, notice many Upstream Interface IGMP/MLD to act on behalf of MN2 and will leave multicast group, whether many Upstream Interface IGMP/MLD agency inquires about MN2 in multicast forward table G1 and G2 entry is last group membership in G1 and G2 group, and this example is "Yes".Many Upstream Interface IGMP/MLD acts on behalf of and learn that MN2 is last group membership in G1, G2 after inquiry, sends special apply for information, confirms do not have group membership, the entry of the multicast forward table of complete deletion G1, G2 group in G1, G2 group.When many Upstream Interface IGMP/MLD agency does not receive the leave message of MN2 but cancelling of MAG-LMA2 tunnel detected, judge whether group G1, G2 recipient quantity are 0, (this example is "Yes"), delete the entry of the multicast forward table of G1, G2 group.

Should be appreciated that above is illustrative and not restrictive by preferred embodiment to the detailed description that technical scheme of the present invention is carried out.Those of ordinary skill in the art can modify to the technical scheme described in each embodiment on the basis of reading specification of the present invention, or carries out equivalent replacement to wherein portion of techniques feature; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the spirit and scope of various embodiments of the present invention technical scheme.Protection scope of the present invention is only limited by following claims.

Claims (7)

1., based on the multicast routing optimization method that many Upstream Interface IGMP/MLD acts on behalf of, it is characterized in that, comprise the following steps:

Described many Upstream Interface IGMP/MLD agency has multiple Upstream Interface;

For transmission multicast address be the multicast source of (S, G), its Upstream Interface used has and only has one; For the multicast receivers that receiving group address is (S, G) or (*, G), its Upstream Interface used has and only has one; The Upstream Interface that multicast source or multicast receivers are using is called actual Upstream Interface; Default upstream interface is called according to the operable Upstream Interface that routing table and policybased routing are selected; * any multicast source comprising S is represented;

The group membership of multicast group comprises mobile node;

The method is further comprising the steps:

S1, when mobile node access downstream links, trigger described many Upstream Interface IGMP/MLD and act on behalf of and send general inquiry message;

After S2, described mobile node receive described general inquiry message, send the multicast group that IGMP/MLD message information adds to described this mobile node request of many Upstream Interface IGMP/MLD Agent Advertisement, and by the actual Upstream Interface of multicast group described in many Upstream Interface IGMP/MLD agent selection; Described IGMP/MLD message information is sent by mobile node and comprises the multi-cast subscriptions information of this mobile node;

After S3, described many Upstream Interface IGMP/MLD agency receives the described IGMP/MLD message information of its lower mobile node transmission of access, set up for described multicast group or upgrade multicast forward table, and periodically sending according to this multicast forward table and integrate IGMP/MLD message information to upstream link corresponding to the actual Upstream Interface of described multicast group;

The multicast packet of S4, described multicast group, by this actual Upstream Interface, is forwarded to its downstream interface according to described multicast forward table by described many Upstream Interface IGMP/MLD agency;

S5, described many Upstream Interface IGMP/MLD agency is by recording group membership's quantity of described multicast group or finding out the existence of Upstream Interface of described multicast group, dynamically upgrade the actual Upstream Interface of described multicast group, and send described integration IGMP/MLD message information by the actual Upstream Interface upgraded.

2. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 1, it is characterized in that, described step S1 is further comprising the steps:

Described mobile node is respectively each group address start-up study timer of the multicast group that will receive, described back off timer is [0, maximum response time] between get a random number, described back off timer is to after date, and described mobile node sends IGMP/MLD message information.

3. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 2, it is characterized in that, described step S3 is further comprising the steps:

When (S, G) exists with (*, G) simultaneously, if the actual Upstream Interface that described integration IGMP/MLD message information is corresponding is different, then (S, G) and (*, G) send respectively to respective actual Upstream Interface and integrate IGMP/MLD message information; Wherein, (*, G) sends and comprises the integration IGMP/MLD message information of (G, Exclude, S) until (S, G) state is cancelled, and S represents the address of multicast source;

Or directly select to (*, G) actual Upstream Interface sends integrates IGMP/MLD message information, until (*, G) cancels, (S, G) could select the default upstream interface of oneself to send as actual Upstream Interface and integrate IGMP/MLD message information.

4. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 3, it is characterized in that, described step S4 is further comprising the steps:

If described many Upstream Interface IGMP/MLD acts on behalf of forward (* according to described multicast forward table to its downstream interface, or (S G), G) while multicast packet, there is the situation that multicast source S sends the multicast packet of multicast group G in its downstream interface, then described many Upstream Interface IGMP/MLD acts on behalf of the downstream interface multicast data forwarding subscribing to this multicast packet to other except downstream interface corresponding to multicast source S, also need the default upstream interface multicast data forwarding to multicast source S, and, subscribe to multicast group (*, G) corresponding actual Upstream Interface need send and comprise (G, Exclude, S) integration IGMP/MLD message information, wherein, the default upstream interface depending on described multicast source S is its actual Upstream Interface,

For the multicast group (S, G) that recipient subscribes to, described many Upstream Interface IGMP/MLD acts on behalf of the IGMP/MLD message information without the need to forwarding to its Upstream Interface about (S, G).

5. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 4, it is characterized in that, described step S5 is further comprising the steps:

Step S51, when described mobile node leaves, send the described many Upstream Interface IGMP/MLD of state variation report notice to act on behalf of, described in described many Upstream Interface IGMP/MLD agents query, whether group membership's quantity of multicast group is 0, if it is step S52 is performed, if not, then perform step S53;

The cache entries of step S52, the directly described multicast group of deletion;

Whether step S53, the described mobile node of continuation inquiry are last group memberships that in described multicast group, actual Upstream Interface is consistent with default upstream interface, if not then performing step S54; If it is step S55 is performed;

Step S54, delete IP address entry about described mobile node;

Step S55, select new actual Upstream Interface;

Or described step S5 is further comprising the steps:

S56, when described in described many Upstream Interface IGMP/MLD delegates perceive, the actual Upstream Interface of multicast group is cancelled, whether group membership's quantity of inquiring about described multicast group is 0, if it is performs step S52, otherwise performs step S55.

6. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 5, it is characterized in that, described step S55 is further comprising the steps:

Described many Upstream Interface IGMP/MLD agency selects according to multicast receivers quantity under the default upstream interface under multicast group different in multicast forward table, and the default upstream interface selecting quantity maximum is as new actual Upstream Interface;

If quantity is identical, then the preferred value pre-set according to default upstream interface, the time of existence or Stochastic choice way selection go out an actual Upstream Interface, rejoin multicast tree;

For the group membership of first multicast group, the default upstream interface of this group membership is as being actual Upstream Interface.

7. the multicast routing optimization method acted on behalf of based on many Upstream Interface IGMP/MLD according to claim 1, is characterized in that,

For the entity running described many Upstream Interface IGMP/MLD agency, the interface on this entity can not become Upstream Interface and downstream interface simultaneously.