JP2007074313A - Network redundancy control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restore information transmission in a short time even in the case of the occurrence of a fault of an information relay device being an exit of a section wherein bypass processing should be performed when a fault occurs. <P>SOLUTION: A multicast LSP based on multicast MPLS technology is set from an information transmitter to information relay device constituting a redundant information relay device group, and a packet is transmitted from the information transmitter to the information relay devices constituting the redundant information relay device group, by the set multicast LSP, and an information relay device A in the redundant information relay device group forwards received information, and another information relay device in the redundant information relay device group forwards the information in the case that a fault occurs in the information relay device A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a network redundancy control method, and more particularly to a network redundancy control method for performing path redundancy in an information transmission network.

  In the information transfer network, when an information relay device on the information transfer route or a line connecting the information relay device becomes a failure, a new route for transferring information is set up to communicate information. It is important to ensure

As a method for setting a new route for transmitting information, there are a method for reconfiguring a route for bypassing a failure point by a route setting protocol, and a failure assumed by MPLS (Multi Protocol Label Switching). There is a method of setting a detour LSP (Label Switched Path) for detouring a location and transferring information by the detour LSP when a failure occurs (for example, see Non-Patent Document 1).
Ping Pan, “Fast Reroute Extensions to RSVP-TE for LSP Tunnels”.

  However, the method of resetting the route by the route setting protocol takes time until the communication is restored.

  The bypass method using MPLS can restore communication in a short time, but in the case of a failure of an information relay device serving as an LSP exit, it depends on route switching by a route setting protocol, and communication recovery in a short time is possible. Have difficulty.

  The present invention has been made in view of the above points, and in a section where information is to be routed, in a section where it is desired to perform a detour processing in the event of a failure, it is possible to restore communication in a short time even in the case of a failure of an information relay device serving as an exit of the section It is an object of the present invention to provide a network redundancy control method that enables the above.

  FIG. 1 is a principle configuration diagram of the present invention.

The present invention (Claim 1) is a network redundancy control method for performing path redundancy in a network for transmitting information,
In a route through which information is transmitted via a plurality of routers, a router that transmits information to the route is an information transmitting device, a router that relays information to a destination information receiving device in the route is an information relay device, In a network having a redundant information relay device group composed of the information relay device and a plurality of information relay devices that relay the information instead of the information relay device in the event of a failure,
A multicast LSP, which is an LSP that copies and forwards the same information packet to a plurality of grounds by a multicast MPLS technique, is set from the information transmission device to a plurality of information relay devices in the redundant information relay device group (step 1).
A packet is transmitted to the information relay device constituting the redundant information relay device group by the multicast LSP set from the information transmitting device (step 2),
The information relay device A in the redundant information relay device group transfers the received information (step 3),
When a failure occurs in the information relay device A (step 4), the packet transmitted to the information relay device configuring the redundant information relay device group by the multicast LSP set from the information transmission device is then transmitted (step 5). An information relay device B different from the information relay device A in the redundant information relay device group transfers (step 6).

The present invention (Claim 2) is the network redundancy control method according to Claim 1,
The information transmitting device transfers priority information for transferring information to each information relay device in the redundant information relay device group to the information relay device, and the information relay device sets the priority to its own device. Set the storage means in the
When a failure occurs, the information is transferred to the information relay device having the next highest priority after the information relay device in which the failure has occurred.

The present invention (Claim 3) is the network redundancy control method according to claim 1 or 2,
In order to check whether the information relay device in the redundant information relay device group is operating normally, the information relay device in the redundant information relay device group can send and receive messages for fault detection to communicate with each other. If it disappears, it is determined that a failure has occurred in the partner information relay device.

Moreover, this invention (Claim 4) is the network redundancy control method of Claim 1 or 2,
From the information relay device (branch relay device) that becomes a branch point of information transfer in the multicast LSP by the multicast MPLS technology to the information relay device in the redundant information relay device group from the information relay device in the redundant information relay device group In order to check whether the relay relay device is operating normally, the branch relay device transmits / receives a message for detecting a failure to / from the information relay device in the redundant information relay device group, and communication becomes impossible. If there is a failure, it is determined that a failure has occurred in the partner information relay device.

The present invention (Claim 5) is the network redundancy control method according to Claim 1 or 2,
When information transfer between the information relay devices in the redundant information relay device group becomes impossible due to the route processing protocol, the information relay device as the information transfer source determines that a failure has occurred, or the branch relay device and the redundant information relay device When information transfer between information relay devices in the information relay device group becomes impossible, the branch relay device determines that a line failure has occurred.

  Further, according to the present invention (Claim 6), when a failure occurs, the branch relay device does not have a failure in the redundant information relay device group, and is next to the information relay device in which the failure has occurred. Information is transferred to information relay devices with higher priority.

  As described above, according to the present invention, as a method of transferring information, a method of transferring by multicast LSP using the multicast MPLS technology is used, and a redundant configuration in which a plurality of routers (hereinafter referred to as endpoint routers) serving as the end points are provided. Thus, the information transmitted from the transmitting terminal reaches a plurality of end point routers by multicast MPLS, and transmits information from a certain router to the receiving terminal. If the router breaks down, it is possible to transfer information from other end-point routers, so it is possible to quickly switch routes in the event of a specific information relay device or section failure, and shorten the service interruption time. Thus, communication reliability can be ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 2 shows a network configuration in the first embodiment of the present invention.

  A network for transmitting information includes an information transmitting terminal 1 for transmitting information to be transmitted, an information receiving terminal 2 for receiving and processing information transmitted from the information transmitting terminal 1, and information transmitted from the information transmitting terminal 1. Is transmitted from the information transmission devices (routers) 3 to 11 for transmitting the information to the information receiving terminal 2.

  In FIG. 2, an information transmission path a which is a path for transmitting information from the information transmission terminal 1 to the information reception terminal 2 is set by the path setting protocol, and an information transmission device (router) which actually transmits information is set. The information transmission devices 3, 4, 6, 8, and 11 that configure the information transmission path a are used, and not all the information transmission devices 3 to 11 that configure the network are used.

  In the information transmission path a shown in FIG. 2, when the section where the detour processing is to be performed when a failure occurs is changed from the information transmission apparatus 3 to the information transmission apparatus 9, As shown in FIG. 3, the information transmission device (router) 3 is used, and the information relay devices that relay information are the information transmission devices (routers) 4, 6, and 8.

  Here, when a failure occurs, other information relay devices that can replace the information relay device 8 are the information relay devices 9 and 10, and the redundant information relay device group α is configured as shown in FIG. A multicast LSP that is an LSP that performs copy transfer of the same information packet to a plurality of grounds is set from the information relay device 3 to the information relay devices 8, 9, and 10 constituting the redundant information relay device group α by the multicast MPLS technology. .

  As a result, as shown in FIG. 4, between the information relay devices 8, 9, and 10 constituting the redundant information relay device group α and the information transmitting device 3 is set by the multicast LSP branched by the information relay devices 6 and 7. The

  According to the configuration of FIG. 4, information transmitted from the information transmission terminal 1 to the information reception terminal 2 is transferred from the information transmission apparatus 3 to the information relay apparatuses 8, 9, and 10 by multicast LSP using the multicast MPLS technique. The packet transmission toward the information receiving terminal 2 is transmitted from the information relay device 8 to transmit the information.

  When setting a multicast LSP, which is an LSP that copies and transfers the same information packet to a plurality of destinations by the multicast MPLS technology, the information transmitting device 3 to be set is a multicast LSP for performing a redundant detour, Information indicating the relay device, information indicating the redundant information relay device, and the priority of the information relay device configuring the redundant information relay device are notified to the information relay device configuring the multicast LSP.

  In the configuration as described above, when information is transferred from the information transmission terminal 1, the information transmission device 3 copies the same information packet to a plurality of grounds by the multicast MPLS technology to the information relay devices 8, 9, and 10. A multicast LSP that is an LSP that performs transfer is set, and these information relay devices are set as a redundant information relay device group α. For each information relay device in the information relay device group α, priority 1 is information relay device 8, priority 2 is information relay device 9, and priority 3 is information relay device 10. In the environment set in this way, in a normal state, when the information transmitting device 3 receives a packet from the information transmitting terminal 1, the information transmitting device 3 transfers the packet to the information relay device 8 having the highest priority.

  If a failure occurs in the information relay device 8, the packet is transferred to the information relay device 9 having the next highest priority after the information relay device 8 via the branch relay device 7.

[Second Embodiment]
In the present embodiment, the priority setting method in the first embodiment will be described. The network configuration in this embodiment is the same as that in the first embodiment.

  FIG. 5 shows an example of setting priorities to redundant information relay devices in the second embodiment of the present invention.

  As shown in the figure, when the information transmission device 3 notifies the information relay devices 8, 9, and 10 constituting the redundant information relay device group α of the priority for transferring the packet received from the information transmission terminal 1. The information relay devices 8, 9, and 10 set the priority order in a storage unit such as a memory of each device. Priorities are set to “1”, “2”, and “3” for each of the information relay devices 8, 9, and 10. In the information transmitting device 3 itself, the priority order is managed by a storage unit such as a memory. In FIG. 5, the packet received by the information relay device 8 having the highest priority is transferred.

[Third Embodiment]
In the present embodiment, an operation for confirming whether the information relay devices constituting the redundant information relay device group α described above are operating normally will be described. The network configuration in the present embodiment is the same as that in the first embodiment described above.

  FIG. 6 shows an operation monitoring method for the redundant information relay device group according to the third embodiment of the present invention.

  In the present embodiment, as shown in FIG. 6, in the information relay devices 8, 9, and 10 constituting the redundant information relay device group α, whether the information relay devices 8, 9, and 10 are operating normally with each other. In order to confirm, the health check message is transmitted / received. When the health check message cannot be received, the information relay device that cannot receive the information determines that the information cannot be transferred. FIG. 6 shows a health check message transmission / reception state between the information relay device 8 and the information relay devices 9 and 10.

  In the information relay devices 8, 9, and 10 constituting the redundant information relay device group α, the health check may be performed on other information devices only from the information relay device that is actually transferring information.

  In addition, in the information relay devices 8, 9, and 10 constituting the redundant information relay device group α, the information relay device 8 that actually transfers information from the information relay devices 9 and 10 that are not actually transferring information. It is also possible to send and receive health check messages.

  The information relay devices 8, 9, and 10 of the redundant information relay device group α monitor the reception status of the health check message in order to determine that the information cannot be transferred. It is also possible to determine not to receive information when a health check message cannot be received in time.

[Fourth Embodiment]
In the third embodiment described above, an example in which a health check message is transmitted and received between redundant information relay devices has been described. In this embodiment, a health check message is transmitted and received between a branch relay device and a redundant information relay device group. An example of monitoring the operation will be described. The network configuration in the present embodiment is the same as that in the first embodiment described above.

  FIG. 7 shows an operation monitoring method between the branch relay device and the redundant information relay device group in the fourth embodiment of the present invention.

  In the present embodiment, as shown in FIG. 7, the information relay devices 8, 9, and 10 constituting the redundant information relay device group α send a health check message to the multicast LSP for confirming whether it is operating normally. To the branch relay devices 6 and 7 that become branch points. When the branch relay devices 6 and 7 cannot receive the health check message from the information relay device, the branch relay devices 6 and 7 determine that the information relay device cannot transfer the information. It is assumed that the health check message is transmitted to the branch relay device nearest to the information relay device to be transmitted.

[Fifth Embodiment]
In this embodiment, an example will be described in which a failure is detected without waiting for the monitoring result by the health check message shown in the third and fourth embodiments. The network configuration in the present embodiment is the same as that in the first embodiment described above.

  FIG. 8 is a diagram for explaining the operation when a failure occurrence is detected in the fifth embodiment of the present invention.

  As shown in the figure, for example, when the link between the information relay device 8 and the branch relay device 6 constituting the redundant information relay device group α fails, the health check message reception monitoring state is not waited. The branch relay device 6 determines that the information relay device 8 can no longer transfer information.

  Further, when the information relay devices 9 and 10 detect that the information transfer to the information relay device 8 cannot be performed by the route processing protocol, the information relay device 8 does not wait for the health check message reception monitoring state. Judge that information transfer is no longer possible.

  In addition, as shown in FIG. 9, in the branch relay device and the information relay device, when checking the operation normality of the information relay device, the failure of the information relay device 8 to which the branch relay device 6 is actually transferring information is If detected, an information transfer start message for instructing the start of information transfer is transmitted to the information relay device 9 which is the next priority, and an information transfer stop message is transmitted to the information relay device 8 which has failed. When the information relay device 9 receives the information transfer start message, it starts transferring information. When the information relay device 8 receives the information transfer stop message, the information relay device 8 stops the information transfer.

  The information relay device 8 is not limited to this when the information transfer is stopped before the information transfer stop message is received.

  Also, as shown in FIG. 10, the branch relay device 6 transmits information only to the information relay device 9 with the next highest priority because the information relay device 8 is in failure. In this case, the branch relay device 6 may not transmit a message for instructing the information relay device to stop information transfer. It is assumed that the branch relay device 6 manages the priority order of the information relay devices 8, 9, and 10 of the redundant information relay device group transmitted from the information transmission device 3 in a storage unit such as a memory.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 11 shows the configuration of an IP network according to an embodiment of the present invention.

  The IP network a shown in FIG. 1 includes information terminals 1 and 2 and a plurality of routers 3 to 10.

  It is assumed that the information terminal 2 is connected to the routers 9 and 10 through the same Ethernet (registered trademark) work.

  The routers 9 and 10 are used as information relay devices in the redundant information relay device group, the routers 3 to 7 are used as branch relay devices, and a multicast LSP that is an LSP that performs copy transfer of the same information packet to a plurality of grounds by the multicast MPLS technology. Set.

Multicast LSP settings are
・ Extensions to RSVP-TE for Point to Multipoint TE LSPs, which are being standardized by IETF A multicast LSP for performing redundant detouring of copying and transferring information packets to a plurality of grounds;
-Information of information relay devices that constitute branch relay devices and information relay devices;
-Instruction information indicating whether the priority of each information relay device and the health check message are transmitted / received between the information relay devices or between the branch relay device and the information relay device;
Is set by an extended protocol by adding a new object for notifying each router that configures a multicast LSP, which is an LSP that performs copy transfer of the same information packet to multiple destinations by multicast MPLS technology, with a Path message. .

  When the above multicast LSP is set, according to the contents of the newly added object, the health check message is transmitted / received between the routers 9 and 10, or between the router 7 and the router 9, and between the router 7 and the router 10 to operate normally Confirm sex.

FIG. 12 shows an example of transmission / reception of a normal health check message according to an embodiment of the present invention.
The figure shows an example of a normal time in which a health check message is sent between information relay devices in a state where the branch relay device 7 is copying and transferring packets to the information relay devices 9 and 10.

  FIG. 13 shows an example when a failure occurs according to an embodiment of the present invention.

  In the state shown in FIG. 12, when the health check message from the router 9 cannot be received by the router 10 as shown in FIG. 13, the router 10 starts transferring information and the router 9 stops transferring.

  In FIG. 14, the health check message is transmitted and received between the branch relay device 7 and the information relay devices 9 and 10 in a state where the branch relay device 7 copies and transfers the packet to the information relay devices 9 and 10. Shows the time. Further, FIG. 15 shows a state where a failure has occurred in the state of FIG. 14, because the router 7 (branch relay device) could not receive the health check message from the router 9 (information relay device). A transfer cancellation message is transmitted to the router 9 and a transfer start message is transmitted to the router 10. As a result, the router 9 stops the transfer, and the router 10 starts the transfer.

  Further, FIG. 16 shows a state in which a failure has occurred in the state of FIG. 14, and the router 7 (branch relay device) cannot receive the health check message from the router 9 (information relay device). The packet transfer to the router 9 is stopped and a transfer start message is transmitted to the router 10, whereby the router 10 starts information transfer.

  The present invention is not limited to the above-described embodiments and examples, and various modifications and applications can be made within the scope of the claims.

  The present invention is applicable to a network to which multicast MPLS is applicable.

It is a figure for demonstrating the principle of this invention. It is a network block diagram in the 1st Embodiment of this invention. It is a figure which shows the information transmission apparatus and information relay apparatus in the 1st Embodiment of this invention. It is a setting example of the multicast LSP in the 1st Embodiment of this invention. It is an example which sets a priority to the redundant information relay apparatus in the 2nd Embodiment of this invention. It is a figure which shows the operation | movement monitoring method of the redundant information relay apparatus group in the 3rd Embodiment of this invention. It is a figure which shows the operation | movement monitoring method between the branch relay apparatus and redundant information relay apparatus in the 4th Embodiment of this invention. It is a figure for demonstrating the operation | movement at the time of detecting the failure generation in the 5th Embodiment of this invention. It is FIG. (1) for demonstrating message transmission at the time of the failure generation in the 5th Embodiment of this invention. It is FIG. (2) for demonstrating message transmission at the time of the failure generation in the 5th Embodiment of this invention. It is a block diagram of the IP network of one Example of this invention. It is an example (the 1) of the normal time of this invention. It is an example (the 1) at the time of failure occurrence of one Example of this invention. It is a normal example (the 2) of one Example of this invention. It is an example (the 2) at the time of failure occurrence of one Example of this invention. It is an example (the 3) at the time of failure occurrence of one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information transmission terminal 2 Information reception terminal 3 Router, information transmission device 4 Router, information relay device 5 Router, information relay device 6 Router, information relay device, branch relay device 7 Router, information relay device, branch relay device 8 Router, information Relay device, information relay device in redundant information relay device group 9 router, information relay device, information relay device in redundant information relay device group 10 router, information relay device, information relay device in redundant information relay device group 11 router, information receiving device 12 Information receiving terminal

Claims (6)

A network redundancy control method for performing path redundancy in a network for transmitting information,
In a route through which information is transmitted via a plurality of routers, a router that transmits information to the route is an information transmitting device, a router that relays information to a destination information receiving device in the route is an information relay device, In a network having a redundant information relay device group composed of the information relay device and a plurality of information relay devices that relay the information instead of the information relay device in the event of a failure,
Set a multicast LSP that is an LSP that performs copy transfer of the same information packet to a plurality of grounds by a multicast MPLS technology from the information transmission device to a plurality of information relay devices in the redundant information relay device group,
A packet is transmitted to the information relay device constituting the redundant information relay device group in the multicast LSP set from the information transmission device,
The information relay device A in the redundant information relay device group transfers the received information,
If a failure occurs in the information relay device A, then the packet transmitted to the information relay device constituting the redundant information relay device group by the multicast LSP set from the information transmitting device is transmitted to the redundant information relay device. A network redundancy control method, wherein an information relay device B different from the information relay device A in the group transfers. The information transmitting device transfers priority information for transferring information to the information relay device to each information relay device of the redundant information relay device group, and the information relay device sets the priority. Set it in the storage means in your device,
2. The network redundancy control method according to claim 1, wherein, when a failure occurs, information is transferred to an information relay device having a second highest priority after the information relay device where the failure has occurred.   In order to confirm whether the information relay device of the redundant information relay device group is operating normally, the information relay device in the redundant information relay device group transmits and receives a message for detecting a failure, and communicates. The network redundancy control method according to claim 1, wherein when the communication cannot be performed, it is determined that a failure has occurred in the partner information relay device.   The information relay device in the redundant information relay device group from the information relay device (branch relay device) serving as a branch point of information transfer in the multicast LSP by the multicast MPLS technology to the information relay device in the redundant information relay device group In order to check whether the relay relay device is operating normally, the branch relay device can communicate with the information relay device in the redundant information relay device group by transmitting / receiving a message for detecting a failure. 3. The network redundancy control method according to claim 1, wherein when there is no longer any problem, it is determined that a failure has occurred in the partner information relay device.   When information transfer between the information relay devices in the redundant information relay device group becomes impossible due to a route processing protocol, the information relay device as the information transfer source determines that a failure has occurred, or 3. The network redundancy control method according to claim 1, wherein, when information transfer between information relay devices in the redundant information relay device group becomes impossible, the branch relay device determines that a line failure has occurred.   When a failure occurs, the branch relay device does not generate a failure in the redundant information relay device group, and the information relay device having the next highest priority after the failed information relay device. 6. The network redundancy control method according to claim 4 or 5, wherein the information is transferred.

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