The address flush method of ether multi-ring network and deviceTechnical field
The present invention relates to the ethernet address refresh technique in data communication, relate in particular to a kind of address flush method and device of ether multi-ring network.
Background technology
In the practical application of Ethernet, extensively adopted various resist technologies, realize the switching between primary path and backup path.So-called ether multi-ring network, refer to that Ethernet forms polycyclic topological structure.Topological structure as shown in Figure 1 forms the ether multi-ring network, and in figure, node S1 to S6 is Ethernet switch, and network B is connected with node S2, and network A is connected with node S5.
For the resist technology of ether multi-ring network, in the standard of formulating at present, the ether multi-ring network is divided into to ring (Ring) and subring (Sub-Ring).So-called ring refers to that a complete ether ring, subring refer to a kind of ether ring be connected with other rings or other networks by interconnecting nodes (Interconnection Node); Interconnecting nodes refers to the common node that simultaneously belongs to two or more ether rings.As shown in Figure 2, comprise a ring and a subring in figure, Ring1 is ring, and Ring2 is subring.The node that Ring1 comprises has S1, S2, S3 and S4, and the link comprised has:<S1, S2 >,<S2, S3 >,<S3, S4 > and<S4, S1 >; The node that Ring2 comprises has S3, S5, S6 and S4, and the link comprised has:<S3, S5 >,<S5, S6 > and<S6, S4 >.It is pointed out that<S3 S4 > link belongs to Ring1 and do not belong to Ring2.
In the ether multi-ring network, in a ring/subring, need to have one section link to be blocked to prevent into ring to the forwarding of data message, this section link is called the ring protection link, and the node that has a ring protection link is called the ring protection link and controls node.In the ether multi-ring network, the switching of primary path and backup path is participated in carrying out by the ring protection link.As shown in Figure 2, in Ring1, node S1 is that the ring protection link is controlled node, with the direct-connected link of the port one 1 of the node S1 ring protection link that is Ring1; In Ring2, node S6 is that the ring protection link is controlled node, with the link of 62 direct port connection of the node S6 ring protection link that is Ring2.Under normal circumstances; the protected data forwarding capability of node S1 port blocked 11; the protected data forwarding capability of node S6 port blocked 62; make the communication path between network B and network A be: network B ← → S2 ← → S3 ← → S5 ← → network A, be repeated to forward and form broadcast storm to prevent protected data.
When the link of ether multi-ring network breaks down; if faulty link is not the ring protection link; the ring protection link is controlled the protected data forwarding capability that node is opened its port that is connected with the ring protection link; and each node also wants refresh address to transmit, make to communicate by letter according to new path transmission between network.As shown in Figure 3, Ring1<S2, S3 > link breaks down, after node S2 detects link failure, the data retransmission function of port blocked 22, and notify other node links that fault has occurred; After ring protection link control node S1 receives signalling trouble, open the protected data forwarding capability of port one 1.In addition, each node on Ring1 also wants refresh address to transmit, and obtains communication path new between network B and network A and is: network B ← → S2 ← → S1 ← → S4 ← → S3 ← → S5 ← → network A.
Accordingly, when the faulty link in the ether multi-ring network recovers, need to recover switching, transmission path when Internet Transmission returns to normal condition.Because transmission path changes, so node also needs to carry out refreshing of addresses forwarding table.
When the ether multi-ring network being safeguarded and protect switching, need to propagate a large amount of control messages, these are controlled message and are automatically propagating in the protection control channel.Automatically the protection control channel has two classes, and a class, corresponding to ring, is called the control channel of ring, and the control channel of ring is configured in ring; Another kind of is corresponding to subring, is called the control channel of subring.The control channel of subring has two kinds of configuration modes, and the first is that the control channel of i.e. subring only is configured in subring, as shown in phantom in Figure 4 without the configuration mode of tunnel (Virtual Channel); The second be the control channel configuration packet of subring containing part and tunnel in subring, so-called tunnel refers to the transmission channel that protocol massages that other networks of being configured in the interconnecting nodes place or other rings (comprising other subrings) are subring provides.As shown in Figure 5, it is upper that the control channel of subring Ring2 not only is configured in subring Ring2, but also be configured on ring Ring1; Be configured in the part (dotted line shown in) of ring on Ring1 and be the tunnel that the protocol massages for subring Ring2 provides.Due to the existence of tunnel, the protocol massages of subring can arrive any one node in subring.
About the problem of subring address flush in the ether multi-ring network, as shown in Figure 6, when ether multi-ring network fault-free, the communication path between network B and network A is: network B ← → S2 ← → S3 ← → S5 ← → network A.Link<S3 as subring Ring2; S5 > while breaking down; the ring protection link is controlled node S5 afterport 51 respective links being detected and breaking down; refresh the addresses forwarding table of self; the protected data forwarding capability of port blocked 51; open the protected data forwarding capability ofport 52, and outwards send the malfunction frame.After node S6 receives the malfunction frame, refresh the addresses forwarding table of self, form new transmission path between network A and network B.After node S5 and node S6 refresh addresses forwarding table separately, network A is issued the protected data of network B by the broadcast of node S5 and node S6, finally can arrive network B, and each node of new transmission path address of learning network A.
From above-mentioned analysis, can find out, when the link occurs fault of subring, subring need to send protocol massages to other network beyond this subring by interconnecting nodes and transmit with the node refresh address of notifying other network.Existing standard to this way to solve the problem is: when the subring topology changes, if and only if interconnecting nodes is received with the protocol massages of address flush information and refreshing self addresses forwarding table from subring, this interconnecting nodes is just constructed new address flush protocol massages, and on continuous other ring or subring that 3 times the protocol massages of structure is forwarded to the interconnecting nodes place; After node in other ring or subring is received this protocol massages, refresh addresses forwarding table separately.
For example: shown in Fig. 7, by Ring1, Ring2, Ring3 and Ring4, formed in the ether multi-ring network, Ring2 is a complete closed loop, the node comprised has S2, S6, S7 and S3, the link comprised has:<S2, S6 >,<S6, S7 >,<S7, S3 > and<S3, S2 >, node S3 is that the protection link is controlled node, the link direct-connected withport 32 is the ring protection link; Ring1 is subring, and the node comprised has S2, S1, S5 and S6, and the link comprised has:<S2, S1 >,<S1, S5 > and<S5, S6 >, node S5 is that the protection link is controlled node, the link direct-connected withport 51 is the ring protection link; Ring3 is subring, and the node comprised has S3, S4, S8 and S7, and the link comprised has:<S3, S4 >,<S4, S8 > and<S8, S7 >, node S4 is that the protection link is controlled node, the link direct-connected withport 42 is the ring protection link; Ring4 is subring, and the node comprised has S5, S9, S10, S11 and S8, and the link comprised has:<S5; S9 >,<S9, S10 >,<S10, S11 > and<S11; S8 >, node S10 is that the protection link is controlled node, the link direct-connected with port one 02 is the ring protection link.
Link<S10 as subring Ring4; S11 > while breaking down; node S10 blocks the protected data forwarding capability of 101 ports; and periodically outwards send fault warning (SF) message by port one 02; node S11 blocks the protected data forwarding capability of 112 ports, and periodically outwards sends the SF message by port one 11.Interconnecting nodes S5 refreshes the addresses forwarding table of self after receiving first the message of the SF with address flush information that node S10 sends, and then constructs address flush (Flush) message, on the control channel of subring Ring1, sends 3 times continuously.After the node of subring Ring1 is received the Flush message, refresh addresses forwarding table separately, after interconnecting nodes S2 on subring Ring1 and S6 receive that Flush message refresh address are transmitted, need the Flush message that structure is new, on the control channel of ring Ring2, send 3 times continuously, after the node of ring Ring2 is received this Flush message, refresh addresses forwarding table separately.Interconnecting nodes S8 refreshes the addresses forwarding table of self after receiving first the message of the SF with address flush information that node S11 sends, and then constructs the Flush message, on the control channel of subring Ring3, sends 3 times continuously.After the node of subring Ring3 is received the Flush message, refresh address is transmitted, after interconnecting nodes S3 on subring Ring3 and S7 receive that Flush message refresh address is transmitted, construct new Flush message, on ring Ring2, send 3 times continuously, after the node of ring Ring2 is received this Flush message, refresh addresses forwarding table separately.
This shows, although existing subring address flush method can guarantee other rings at subring interconnecting nodes place or the node in subring and obtain address flush, but diffusion has but occurred in the address flush message of subring interconnecting nodes structure, this will cause that all node refresh addresses on tunnel transmit, cause occurring in all rings of ether multi-ring network and subring the broadcast storm of moment, thereby greatly affect the overall performance of ether multi-ring network.
Summary of the invention
In view of this, main purpose of the present invention is to provide a kind of address flush method and device of ether multi-ring network, to reduce the moment broadcast storm of ether multi-ring network, improves the performance of ether multi-ring network.
For achieving the above object, technical scheme of the present invention is achieved in that
The invention provides a kind of address flush method of ether multi-ring network, the method comprises:
On the unobstructed path between the interconnecting nodes of the subring of ether multi-ring network, configuration refreshes passage;
When the subring topology of described ether multi-ring network changes, and when the interconnecting nodes of the subring that topology changes need to send the address flush message outside described subring, described address flush message is sent to the described node refreshed on passage, to refresh, describedly refresh address of node on passage and transmit.
The described mode of passage by linear virtual LAN VLAN and/or multicast medium access control MAC Address that refresh is configured.
Before the interconnecting nodes of the subring changed in described topology outwards sends the address flush message, the method further comprises: the interconnecting nodes of the subring that described topology changes, refresh the addresses forwarding table of self according to the fault warning SF message of the address flush information of carrying of receiving.
The method further comprises: the described node refreshed on passage refreshes the addresses forwarding table of self after receiving described address flush message, and gives the described subsequent node refreshed on passage by described address flush message repeating.
The method further comprises: when there is choke point in the node of the described address flush message of reception on refreshing passage, judge that described choke point belongs to ring or subring; If belong to ring, the described node of choke point that exists sends the protocol massages that carries address flush information on the control channel of the ring that has described choke point; If belong to subring, the described node of choke point that exists sends and carries the protocol massages of address flush information on the control channel of the subring that has described choke point, and the interconnecting nodes that triggers described subring produces new address flush message and sends to the subsequent node refreshed on passage.
The present invention also provides a kind of address flush device of ether multi-ring network, and this device comprises:
Refresh the passage configuration module, for configuration on the unobstructed path between the interconnecting nodes of the subring at the ether multi-ring network, refresh passage;
The address flush module, for the subring topology at described ether multi-ring network, change, and when the interconnecting nodes of the subring that topology changes need to send the address flush message outside described subring, described address flush message is sent to the described node refreshed on passage, to refresh, describedly refresh address of node on passage and transmit.
Described address flush module further comprises:
The judgement submodule, whether the node that refreshes receiver address update on passage for judgement exists choke point, and judges that described choke point belongs to ring or subring;
Protocol massages sends submodule, for the judged result according to described judgement submodule, while belonging to ring in choke point, sends the protocol massages that carries address flush information on the control channel of the ring that has described choke point; When choke point belongs to subring, send on the control channel of the subring that has described choke point and carry the protocol massages of address flush information, and the interconnecting nodes that triggers described subring produces new address flush message and sends to the subsequent node refreshed on passage.
The described form of passage by linear VLAN and/or multicast mac address that refresh is configured.
The address flush method of a kind of ether multi-ring network provided by the present invention and device, in the topology of subring, change and interconnecting nodes need to send the Flush message outside subring the time, the Flush message only refreshes between the subring interconnecting nodes address of node on unobstructed path and transmits, thereby the Flush message that the interconnecting nodes that makes subring sends to other ring or subring only refreshes the node on a unobstructed path between interconnecting nodes, avoided the Flush message to spread in other ring or subring, avoided all nodes on other network of interconnecting nodes to be refreshed address, reduced the moment broadcast storm of ether multi-ring network, improved the performance of ether multi-ring network.
The accompanying drawing explanation
The topological diagram that Fig. 1 is ether multi-ring network in prior art;
Fig. 2 is communication path topology figure when in prior art, ether multi-ring network link is intact;
Fig. 3 is communication path topology figure during ether multi-ring network link failure in prior art;
Fig. 4 is the schematic diagram that in prior art, the subring control channel is the first configuration mode;
Fig. 5 is the schematic diagram that in prior art, the subring control channel is the second configuration mode;
The schematic diagram of refresh address when Fig. 6 is prior art neutron central link fault;
Fig. 7 is the propagation schematic diagram of Flush message between the subring interconnecting nodes in prior art;
The schematic diagram that Fig. 8 is the communication path between network A of the present invention and network B during without link failure;
The schematic diagram of communication path when Fig. 9 is the subring link failure between network A of the present invention and network B;
The flow chart of the address flush method that Figure 10 is a kind of ether multi-ring network of the present invention;
Figure 11 is the address flush schematic diagram of the embodiment of the present invention when refreshing the passage fault-free;
The address flush schematic diagram one that Figure 12 is the embodiment of the present invention when refreshing passage and have Single Point of Faliure;
The address flush schematic diagram two that Figure 13 is the embodiment of the present invention when refreshing passage and have Single Point of Faliure;
The composition structural representation of the address flush device that Figure 14 is a kind of ether multi-ring network of the present invention.
Embodiment
Below in conjunction with the drawings and specific embodiments, the technical solution of the present invention is further elaborated.
The present invention analyzes and can find by the ether multi-ring network address flush process in practical application, and all other rings at refresh all interconnecting nodes place or the address of node in subring are transmitted and be there is no need.For example, in the ether multi-ring network shown in Fig. 8, Ring2 is ring, and Ring1, Ring3 and Ring4 are subrings; Node S3, S5, S4 andS 10 are that the protection link is controlled node, and the link direct-connected withport 32,port 51,port 42 and port one 02 is the ring protection link; Interconnecting nodes in the ether multi-ring network has S3, S7, S2, S6, S5 and S8.In the trouble-free situation of ether multi-ring network, the communication path between network A and network B is: network B ← → S4 ← → S3 ← → S2 ← → S6 ← → S7 ← → S8 ← → S11 ← → S10 ← → network A.Again as shown in Figure 9; link<S10 as subring Ring4; S11 > while breaking down; node S10 blocks the protected data forwarding capability of 101 ports; and open the protected data forwarding capability of 102 ports; node S11 blocks the protected data forwarding capability of 112 ports, and the communication path between network A and network B becomes: network B ← → S4 ← → S3 ← → S2 ← → S1 ← → S5 ← → S9 ← → S10 ← → network A.
Comparing cell A and network B two communication paths in Fig. 8 and Fig. 9, can find that two communication paths have common path: S4 ← → S3 ← → S2; That is to say at subring link<S10, S11 > when breaking down, node S3 and S4 needn't transmit by refresh address, only refresh unobstructed path between the interconnecting nodes of subring of ether multi-ring network (S5 ← → S1 ← → S2 ← → S6 ← → S7 ← → S8) on address of node transmit, just can guarantee that data can not forward along wrong path.
Therefore, the basic ideas that can determine address flush method of the present invention are: when the topology of the subring of ether multi-ring network changes, and, when the interconnecting nodes of the subring that changes of topology need to send the Flush message outside this subring, the Flush message only refreshes between the subring interconnecting nodes address of node on unobstructed path and transmits.
The address flush method of a kind of ether multi-ring network of the present invention that the basic thought based on above-mentioned is realized as shown in figure 10, mainly comprises the following steps:
Step 1001, on the unobstructed path between the interconnecting nodes of the subring of ether multi-ring network, configuration refreshes passage (Flush Channel).
Refreshing passage and can realize by configuration linear VLAN (VLAN, Virtual LocalAreaNetwork) mode in the present invention, the passage that refreshes of configuration is identified by unique VLAN ID; Also can realize by the mode of configuration multicast medium access control (MAC, MediaAccess Control) address; Can also in conjunction with the mode of multicast mac address, realize by linear VLAN.
Step 1002, when the subring topology of ether multi-ring network changes, the interconnecting nodes of the subring that topology changes refreshes the addresses forwarding table of self according to the message of the SF with address flush information received, and refreshing on passage of the subring changed in this topology sends the Flush message.
The present invention can be defined as YY by the target MAC (Media Access Control) address of Flush message, and YY can adopt in G.8032 reserved 01-19-A7-00-00-01 and 01-19-A7-00-00-EF, or adopts 01-19-A7-00-00-00.Can be determined according to actual needs.
Step 1003, after the refreshing node on passage and receive the Flush message of the subring that topology changes, refresh addresses forwarding table separately.
Step 1004, judgement receives the node of this Flush message refreshing on passage whether choke point is arranged, if having, performsstep 1006; Otherwise, performstep 1005.
Step 1005, the node that judge to receive this Flush message does not have choke point refreshing on passage, and continues to forward this Flush message by this node refreshing on passage.
Step 1006, judgement is that the port of ring has this choke point, or the port of subring has this choke point, if the port of ring has this choke point, performsstep 1007; If the port of subring has this choke point, performstep 1008.
Step 1007, this node sends the protocol massages that carries address flush information on the control channel of the ring that has this choke point.Node on the ring, from control channel receives this protocol massages, refreshes addresses forwarding table separately according to the address flush information in protocol massages.
The present invention can adopt R-APS (sp_flush) protocol massages as the protocol massages that carries address flush information, and the transmission of R-APS (sp_flush) protocol massages on control channel do not affect the protocol massages that other transmit on control channel.
Step 1008, this node sends the protocol massages that carries address flush information on the control channel of the subring that has this choke point.After having node in the subring of this choke point and receiving this protocol massages, refresh addresses forwarding table separately, and the interconnecting nodes of this subring after transmitting, refresh address also produces new Flush message and sends to the subsequent node refreshed on passage.
Address flush method below in conjunction with specific embodiment to the invention described above further elaborates.As shown in figure 11 for refreshing the embodiment of the address flush under the passage non-failure conditions.In figure, Ring1, Ring2, Ring3 and Ring4 form the ether multi-ring network.Ring2 is a complete closed loop, and the node comprised has S2, S6, S7 and S3, and the link comprised has:<S2, S6 >,<S6, S7 >,<S7, S3 > and<S3, S2 >, node S3 is that the protection link is controlled node, the link direct-connected with port 32 is the ring protection link; Ring1 is subring, and the node comprised has S2, S1, S5 and S6, and the link comprised has:<S2, S1 >,<S1, S5 > and<S5, S6 >, node S5 is that the protection link is controlled node, the link direct-connected with port 51 is the ring protection link; Ring3 is subring, and the node comprised has S3, S4, S8 and S7, and the link comprised has:<S3, S4 >,<S4, S8 > and<S8, S7 >, node S4 is that the protection link is controlled node, the link direct-connected with port 42 is the ring protection link; Ring4 is subring, and the node comprised has S5, S9, S10, S11 and S8, and the link comprised has:<S5; S9 >,<S9, S10 >,<S10, S11 > and<S11; S8 >, node S10 is that the protection link is controlled node, the link direct-connected with port one 02 is the ring protection link.
The control channel of subring Ring4 is divided into two parts: tunnel and subring Ring4 part.It is upper that the tunnel of subring Ring4 is configured in Ring1, Ring2 and Ring3, and control node S3, S4 on tunnel and S5 have blocking action to the message of subring Ring4.
Node S5 and S8 are the interconnecting nodes that subring Ring4 accesses other ring or subring, and the passage that refreshes of subring Ring4 is configured on following path: S5 ← → S1 ← → S2 ← → S6 ← → S7 ← → S8, as shown in phantom in FIG..The passage that refreshes of subring is realized by configuring linear VLAN.
Link<S10 of subring Ring4 in figure, S11 > fault has occurred, the ring protection link is controlled the protected data forwarding capability thatnode S 10 opens 102 ports, the data retransmission function of blocking 101 ports, and outwards periodically send the SF message along 102 ports.Node S11 blocks the protected data forwarding capability of 112 ports, and outwards periodically sends the SF message along 111 ports.
When interconnecting nodes S5 receives the message of the SF with address flush information that S10 sends first, refresh the addresses forwarding table of self, and structure Flush 1 (MAC Address is YY) message, this message transmits refreshing on passage of subring.After refreshing node S1, S2, S6, S7 and S8 on passage and receivingFlush 1, refresh addresses forwarding table separately.It is pointed out that because the SF message is periodically to send, only have and receive that first the SF message just can cause that interconnecting nodes S5 carries out the operation of address flush and triggering for generatingFlush 1, follow-up SF message can not cause the corresponding operating of interconnecting nodes S5.
Similarly, when interconnecting nodes S8 receives the message of the SF with address flush information that S11 sends first, refresh the addresses forwarding table of self, and structure Flush 2 (MAC Address is YY) message, this message transmits refreshing on passage of subring.After refreshing node S7, S6, S2, S1 and S5 on passage and receiving this message, also refresh addresses forwarding table separately.
This shows, the Flush message of subring Ring4 along refresh passage (the unobstructed path S5 between the interconnecting nodes of subring Ring4 ← → S1 ← → S2 ← → S6 ← → S7 ← → S8) refreshed, node S3 and S4 do not have refresh address to transmit, thereby have greatly reduced the quantity of the node that ether multi-ring network refresh address transmits.And, so can guarantee that data can not forward along wrong path.
As shown in Figure 12 and Figure 13 for refreshing in passage the embodiment that has the address flush in the Single Point of Faliure situation.S5 and S8 node are the interconnecting nodes that subring Ring4 accesses other ring or subring, and the passage that refreshes of subring Ring4 is configured on following path: S5 ← → S1 ← → S2 ← → S6 ← → S7 ← → S8.In Figure 12, subring Ring4 does not have fault, but its refresh on passage<S6, S7 > Single Point of Faliure occurred in link.Ring Ring2 protects and switches, and the node refresh address on ring is transmitted.Communication path between network A and network B is: network B ← → S4 ← → S3 ← → S7 ← → S8 ← → S11 ← → S10 ← → network A.
In Figure 13, subring Ring4<S10, S11 > fault occurred again in link, and node S10 opens the protected data forwarding capability of 102 ports, the data retransmission function of port blocked 101, and outwards periodically send the SF message along 102 ports.The protected data forwarding capability of node S11 port blocked 112, and outwards periodically send the SF message along port one 11.
When interconnecting nodes S5 receives the message of the SF with address flush information that node S10 sends first, interconnecting nodes S5 refreshes the addresses forwarding table of self, and structure Flush 1 (MAC Address is YY) message, and this message transmits refreshing on passage of subring.
After refreshing node S1, S2 on passage and receivingFlush 1, refresh addresses forwarding table separately.Wherein node S6 receives afterFlush 1 that also refresh address is transmitted, but it finds that obstruction has occurred theport 63 refreshed on passage, node S6 sends R-APS (sp_flush 1) protocol massages on the control channel of ring Ring2 (comprising port blocked 63), and this protocol massages will cause that node S2, S3 and the S7 refresh address of ring on Ring2 transmit.
Similarly, when interconnecting nodes S8 receives the message of the SF with address flush information that node S11 sends first, interconnecting nodes S8 refreshes the addresses forwarding table of self, and structure Flush 2 (MAC Address is YY) message, and this message transmits refreshing on passage of subring.
After refreshing node S7 on passage and receivingFlush 2, refresh the addresses forwarding table of self, and find that obstruction has occurred theport 72 refreshed on passage, so node S7 sends R-APS (sp_flush 2) protocol massages on the control channel of ring Ring2 (comprising port blocked 72), this protocol massages will cause that node S3, S2 and the S6 refresh address of ring on Ring2 transmit.
In sum, unobstructed path S5 ← → S1 ← → S2 ← → S3 ← → S7 ← → node on S8 all carried out address flush.Network A and network B can communicate along correct path subsequently.Network B ← → S4 ← → S3 ← → S2 ← → S1 ← → S5 ← → S9 ← → S10 ← → network A is by top analysis, we can find out subring Ring4 refresh passage generation Single Point of Faliure after, this programme still can guarantee that the ether multi-ring network normally moves.
For realizing the address flush method of the invention described above, the present invention also provides a kind of address flush device of ether multi-ring network, and as shown in figure 14, this device comprises: interconnectivepassage configuration module 10 and the address flush module 20 of refreshing.Refreshpassage configuration module 10, for configuration on the unobstructed path between the interconnecting nodes of the subring at the ether multi-ring network, refresh passage; Refreshingpassage configuration module 10 can adopt the form configuration of linear VLAN and/or multicast mac address to refresh passage.The address flush mould determines 20, for the subring topology at the ether multi-ring network, change, and when the interconnecting nodes of the subring that topology changes need to send the address flush message outside subring, the address flush message is sent to the node refreshed on passage, to refresh this, refresh address of node on passage and transmit.
Wherein, address flush module 20 further comprises:interconnective judgement submodule 21 and protocol massages send submodule 22.Judgement submodule 21, whether the node that refreshes receiver address update on passage for judgement exists choke point, and judges that this choke point belongs to ring or subring.Protocol massages sendssubmodule 22, for the judged result according tojudgement submodule 21, while belonging to ring in choke point, sends the protocol massages that carries address flush information on the control channel of the ring that has choke point; When choke point belongs to subring, send the protocol massages that carries address flush information on the control channel of the subring that has choke point, and the interconnecting nodes of triggering subring produces new address flush message to the subsequent node transmission refreshed on passage.
The above, be only preferred embodiment of the present invention, is not intended to limit protection scope of the present invention.