WO2005117365A1

WO2005117365A1 - Communication control apparatus and communication control method

Info

Publication number: WO2005117365A1
Application number: PCT/JP2005/010013
Authority: WO
Inventors: Takehiko Kashiwagi; Soichiro Araki; Kazuya Suzuki; Masahiro Jibiki
Original assignee: Nec Corporation
Priority date: 2004-05-28
Filing date: 2005-05-25
Publication date: 2005-12-08
Also published as: JPWO2005117365A1

Abstract

In a communication control apparatus (200) provided at a node of a network that constitutes paths to enable a connection type of communication, the number (T) of minimum paths to be reserved is established, and when the number of currently available paths falls short of the number (T) due to a trouble, a path establishment and a signaling are performed to reserve paths anew, thereby reducing the frequency of signaling for reserving paths anew. This can diminish a high load state caused by avoiding the line trouble in the network, provide a high-speed resolution of trouble, and realize a highly-reliable network.

Description

Description Communication control device and communication control method

The present invention relates to a communication control device and a communication control method, and more particularly to a communication control device and a communication control method for setting a path. Background art

In recent years, MP LS (Mu ti-Protoco I — Lab I — Switching power ^λ note) has been described as a packet transmission method that can guarantee the communication quality for voice and stream traffic in IP networks. .

MPLS is a technology that enables connection-based communication by creating a path called LSPel (Label Swit t ched Pat) on a connectionless IP network.

In general, data transfer between routers used on the Internet uses IP headers as routing (route selection) information. MPLS uses short fixed-length identification signs called labels instead of IP headers. I do. Within a network composed of MPLS compatible routers (Label-Switching Router), it is possible to separate transfer processing and path calculation processing, reducing the load on individual routers and increasing processing speed. Is achieved. It also enables more advanced communication quality control (QoS) and the construction of a private network independent of the network configuration.

In a network using MPLS, in addition to the currently secured path (hereinafter referred to as the working path), a path that is switched when a failure occurs in the working path (hereinafter referred to as a protection path) is set. When the occurrence is detected, the communication control device in the router switches the path and can transmit the packet bypassing the failure. Similarly, in an ATM network using a virtual path, a working path and a protection path are set in the same manner, and when a failure occurs, the working path is switched to a protection path. You are bypassing the obstacle.

As disclosed in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2003-224442), a conventional path switching method includes setting a working path and a protection path in advance, and A line identification number for identifying the line is allocated to each line in the network, and a set of line numbers that do not affect communication is registered and managed as a path management table for each path, so that a failure in the network can be prevented. When a failure occurs, a method is used in which the device that detects the failure notifies the target device of the line identification number, and based on the notification, refers to the path management table to determine whether switching is necessary and switches the path. ing.

Figure 1 shows the flow from the detection of a fault that occurred on the working path to the securing of the path according to the conventional technology. When the conventional communication controller detects a path failure (step S1), it switches the working path to the protection path by the above-described method (step S3), updates the routing table (step S5), and resets the path. The replaced backup path is secured by signaling (step S7). At this time, it sends and receives updated routing information to and from other nodes in the network and sends and receives signaling information to secure paths.

In the conventional technology, signaling and routing information to be changed and retried are performed each time a failure occurs, such as in a network using a narrow band network or a wireless section in which the line is not stable. In a network where line failures occur frequently, the load of such information increases, which hinders data transmission. Disclosure of the invention

An object of the present invention is to provide a communication control device and a communication control method capable of reducing a high load state due to routing information and signaling information when a line failure occurs in a network.

Another object of the present invention is to provide a communication control device and a communication control method capable of coping with a line failure according to the characteristics of the network and the needs of the user.

A communication control device according to the present invention, a communication control method according to the present invention, and a communication control program according to the present invention are as follows.

(1) Routing connected to at least one other node via a communication network An information processing unit;

A routing processor connected to the routing information processing unit and the signaling processor, and a path control processing unit connected to the other node via the communication network;

The routing information processing unit transmits and receives routing information for routing data to and from the other node, and detects a path failure based on the received routing information and causes the path management processing unit to fail. Submit information,

The path management processing unit holds the minimum number of paths T to be reserved, calculates the number of currently reserved paths R in consideration of the received failure information, and precedes the R. In comparison with T, when R <T, it is determined that a new path is to be secured, a path setting for newly securing the path is performed, and the contents of the path setting are described in the routing information processing. A path setting command based on the contents of the path setting to the signaling processor,

The routing information processing unit transmits routing information based on the content of the path setting to the other node,

The communication control device, wherein the signaling processor performs signaling with the other node based on the received path setting command to newly secure a path set in the path management processing unit.

(2) The communication control device according to (1), wherein

The number of new passes to be secured is D,

If the maximum number of passes that can be secured is M,

The data management processing unit holds the D, which is an arbitrary fixed value satisfying T≤R + D≤M, and when R <T, sets a path setting for newly securing the D paths. A communication control device for reserving the D paths.

(3) In the communication control device according to (2),

The path management processing unit is connected to an external device, receives any D satisfying T≤R + D≤M from the external device, and newly secures the D paths when R <T. A communication control device for setting a path for the communication and newly securing the D paths. (4) The communication control device according to (2), wherein

It has a history storage unit,

The history storage unit records a reserved duration of the path in the past and a probability that the path has failed,

The communication control device, wherein the path management processing unit calculates the D from the duration and the probability.

(5) The communication control device according to (4), wherein

The history storage unit records, in a time-series manner, the duration of the path being secured and the probability that the path has failed,

(6) The communication control device according to (1), wherein

A routing table connected to the routing information processing unit, wherein the routing table records routing information for performing routing of data received from the other node, and the routing information processing unit Rewriting a routing table based on the contents of the path setting received from the path management processing unit, and transmitting the routing information based on the contents of the path setting to the other node. Communication control device.

(7) The communication control device according to (1), wherein

A data buffer, a data receiving unit connected to the other node via a network, and a data transmitting unit;

The data buffer is connected to the data receiving unit and the data transmitting unit, and when R is 0, records data received by the data receiving unit;

The communication control device, wherein when the path force << newly secured and 0 <R, the data transmission unit transmits the data stored in the data buffer to the other node.

(8) In a communication network in which a link is formed by a plurality of nodes, a communication system mounted on the node and setting a path to be used for data transmission. Your way,

Detecting a failure of the failed path;

Calculating the number of currently reserved paths R, taking into account information on the detected faults;

A step of setting a path for newly securing a path when R <T by comparing with the number T of paths to be secured at a minimum;

Transmitting routing information based on the content of the path setting to the other node,

A step of performing signaling with the other node based on the contents of the path setting to newly secure the path.

(9) In the communication control method according to (8),

The number of new passes to be secured is D,

If the maximum number of passes that can be secured is M,

Holding the 0 satisfying D ≤ +0 ≤ 1 \ / 1, and setting a path for newly securing the D paths when R <T;

A step of newly securing the D paths based on the path setting.

(10) In the communication control method according to the above (9),

Receiving said D satisfying T≤R + D≤M from outside;

When R <T, setting a path for newly securing the D paths and newly securing the D paths based on the path settings. Communication control method.

(11) The communication control method according to (9), wherein

Recording the duration of the path in the past and the probability that the path failed;

Calculating the D from the duration and the probability.

(1 2) The communication control method according to (9), wherein

In time series, the secured duration of the path and the probability that the path failed Recording;

Calculating the D from the duration and the probability.

(13) The communication control method according to (8), wherein

Rewriting a routing table for routing data received by the node based on routing information including the contents of the path setting;

A step of transmitting the routing information to another node.

(14) The communication control method according to (8), wherein

Recording the data received by the node if the R is 0, and securing the path and transmitting the data to the other node if 0 <R. Communication control method.

(15) A communication control program for realizing the communication control method according to claim 8 by a computer.

INDUSTRIAL APPLICABILITY The communication control device according to the present invention can be applied to any type of bucket communication network as long as the transmission method enables connection-type communication by setting a path. The invention's effect

ADVANTAGE OF THE INVENTION According to the communication control apparatus and method of this invention, the high load state by the routing information divided by the signaling information at the time of a circuit failure occurring in a network can be reduced.

Further, according to the communication control device and method of the present invention, it is possible to cope with a line failure according to the characteristics of the network and the needs of the user. Brief Description of Drawings

FIG. 1 is a flowchart for explaining an operation from a failure detection to a path securing according to the conventional technique.

Figure 2 shows a network composed of multiple nodes to which the present invention is applied. FIG.

FIG. 3 is a diagram for explaining an example of a virtual path configured in the network shown in FIG.

FIG. 4 is a block diagram of the communication control device according to the first embodiment of the present invention. FIG. 5 is a diagram used to explain the operation of the communication control device when the communication control device of FIG. 4 is mounted on a certain node in a network.

FIG. 6 is a flowchart for explaining the operation of the communication control device according to the present invention from the detection of a failure to the securing of a new path.

FIG. 7 is a block diagram of a communication control device according to the second embodiment of the present invention.

FIG. 8 is a block diagram of the communication control device according to the third embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

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

FIG. 2 is a diagram showing a network 100 constituted by a plurality of nodes 30, 50,... To which the present invention is applied. The network 100 is a network having an unstable line in which a failure is likely to occur, such as a wireless communication network or a narrow band network.

In such a network 100, each node (for example, a certain node 30) constitutes a plurality of virtual paths (for example, paths 111 to 115) as shown in FIG. As a result, it is possible to secure connection-type communication in which various types of packet data such as voices and images are transmitted from a certain node 30 to the partner node 50.

Referring to FIG. 4, there is shown a communication control device 200 according to a first embodiment of the present invention. The communication control device 200 is mounted on each node of the network 100 shown in FIG. 1 (or FIG. 2).

The communication control device 200 is, for example, a path that is mounted on a certain node 30 in the network 100 in the state shown in FIG. When a failure such as a transmission failure or equipment failure occurs in the working path), it switches to a spare path that is not being used (hereinafter referred to as a protection path) and bypasses the failure by securing a protection path. The goal is to obtain a reliable network. In FIG. 4, the communication control device 200 includes a routing information processing section 31, a signaling processor 32, and a path management processing section 33. The routing information processing unit 31 is connected to an adjacent other node 40 via a network 100 (FIG. 5). The signaling processor 32 is also connected to the other node 40 via the network 100. The path management processing unit 33 is connected to the routing information processing unit 31 and the signaling processor 32.

The routing information processing unit 31 transmits / receives routing information 201 including information on a node on the working path, information on a used band, and information necessary for routing to / from another node 40, and When the occurrence of a failure in the active path is detected, the failure information 202 is transmitted to the path management processing unit 33. The signaling processor 32 is controlled by the path management processing unit 33, and in accordance with a path setting instruction 203 from the path management processing unit 33, to secure a backup path with the partner node 50 (FIG. 5). Signaling is performed with the nodes on the backup path to secure the path.

The path management processing unit 33 detects a failure from the failure information 202, manages the working path and the backup path, holds the minimum number of paths T to be secured, and considers the failure information 202. Determine the number R of working paths (paths currently secured) placed in the network, make path settings, notify the routing information processing unit 31 of the contents of the path settings, and control the signaling processor 32. Part.

Specifically, the path management processing unit 33 monitors the routing information processing unit 31 and identifies the active path in which a failure has occurred based on the failure information 202 received from the routing information processing unit 31. Then, calculate the number R of working paths other than the working path in which a failure has occurred. Next, the path management processing unit 33 compares the number T of the paths to be kept to the minimum and holds it, and if R <T, determines the number D of the paths to be newly reserved, and The backup path is set as the new working path. In this way, when the path management processing unit 33 sets the path for newly securing the D paths, the path management processing unit 33 notifies the routing information processing unit 31 of the contents of the route setting 203 and the signaling. A path setting command 204 based on the contents of the path setting is sent to the processor 32.

The routing information processing section 31 executes a routine based on the path setting content 202. The other node 40. The signaling processor 32 performs signaling with the other node 40 based on the received path setting instruction 204, and newly secures the path set in the path management processing unit 33. In this way, the signaling processor 32 secures the D backup paths as new working paths based on the path setting command 204.

In FIG. 6, from the detection of a failure of the communication control device 200 (FIG. 4) in a certain node 30 when a failure 1 occurs in the network 100 shown in FIG. Is shown.

Referring to FIG. 6, in FIG. 5, between the nodes 30 and 50 in the network 100, there are three working paths (paths 1 1 1 to 1 13) and three backup paths. When this is set (path 2 11 to path 2 13), the operation of the communication control device 200 (FIG. 4) of a certain node 30 when the failure 1 occurs in the path 1 13 explain. Assuming that a node adjacent to a certain node 30 is another node 40, when a failure 1 occurs in the path 1 13, the routing information processing unit 31 in the certain node 30 receives from the other node 40 A failure is detected based on the routing information to be transmitted, and failure information 202 is transmitted to the path management processor 33 (step S 2).

Based on the received failure information 202, the path management processing unit 33 identifies that the path having the failure is the path 113, and changes the number R of the working paths from 3 to 2 (S Step S 4).

Next, it is checked whether the number of working paths R is 0 (there is no normal path having no failure) (step S 6), and since the number of working paths is R = 2, the number of paths to be secured D Is determined (step S8).

The path management processing section 33 holds the minimum number of paths T (T≤M), where M is the maximum number of paths that can be secured. The minimum number of paths T to be reserved and the number of active paths R are compared. If R is less than T, that is, if R <T, the path switching is determined and the number of paths to be newly reserved D To determine. In the case of R≥T, D = 0.

For example, if the minimum number of paths to be reserved is T = 1 or 2, then R = 2, so R≥T, and the number of paths to be newly reserved is D = 0. But T If = 3, then R and T, so the number D of newly secured paths is determined. Furthermore, by setting the number of paths that can be secured to the maximum as M and setting a fixed value D that satisfies T ≤ R + D ≤ M as the number of newly secured paths, the number of newly secured paths is limited. When R <T, at least D paths can be secured. For example, if M = 5 and T = 3, the number D of newly secured paths is set to any fixed value in the range of 1 to 3, and up to three new paths (maximum 3) Switching of book paths) is possible. At this time, if, for example, D = 2, if R <T, that is, if R is 0, 1, or 2, it will always operate to newly secure two paths, and R≥ Until T is reached, a new one path is newly secured (one path is switched).

Referring to FIG. 7, there is shown a communication control device 200 'according to a second embodiment of the present invention. The communication control device 200 'includes similar parts indicated by similar reference numerals. In the communication control device 200 ′, T and D set in the path management device 33 are set by the external device 500 which is, for example, NMS (Network Management System), or, for example, It is set by the user using the external device 500 as an input device, and can be changed at any time and from any location.

Returning to FIG. 6, the continuation of the operation of the communication control device 200 (FIG. 4) provided in a certain node 30 of the network 100 in FIG. 5 will be described.

As described above, the path management processing unit 33 determines whether or not D is 0 after the number D of paths to be newly secured is determined in step S8 by comparing R and T (step S10). . If D = 0, no new path is set. However, when D is not 0, for example, when D = 2, a new path setting (path switching) for setting two backup paths as the working path is performed, and the path setting content (path switching content) 203 is set. The routing information processing unit 31 is notified (step S12). The routing information processing unit 31 notified of the path setting content (path switching content) 203 transmits the routing information 201 including the path setting content (path switching content) to the other node 40, and is required. If this is the case, update the routing table (step S14). The path management processing unit 33 that has determined the new path setting (path switching) selects the path to be newly established, and transmits a path setting instruction 204 to the signal processor 32. For example, when D = 2, the path management processing unit 3 3 selects the paths 2 1 1 and 2 1 2 from the backup paths in FIG. 5 as the newly secured paths, and sends the path 2 1 1 to the signaling processor. 1 and a path setting command 204 for securing the path 2 1 2 are transmitted. The signaling processor 32 communicates with the signaling processors of the nodes on the paths 211 and 212 to secure a new path (step S16). In this way, the signaling processor 32 secures the D backup paths as new working paths.

As described above, when a failure occurs in the working path, setting the minimum number of paths T to be reserved allows the path setting (path disconnection) until the number of working paths R satisfies R <T. Switching), the transmission and reception of routing information that occurs every time a path is set up (path switching), and the need to use frequent signaling to secure a path are eliminated. The load of sending and receiving routing information and signaling for securing paths can be reduced.

In step S6 described above, if all the working paths have failed and the number of working paths has run out (R = 0), the path management processing unit 33 checks the remaining number of backup paths and checks for a new path. It is determined whether or not it is possible to secure (Step S 9). If a backup path exists and a path can be secured, the process proceeds to step S8 for determining the number D of paths to be newly secured.

Referring again to FIG. 7 in addition to FIG. 6, the communication control device 200 ′ has a data buffer 36, and when a new path cannot be secured, the other communication control device 300 of another node. Is stored in the temporary data buffer 36 (step S11).

Routing from another node 'Release failure 201 and a new link are notified to the routing information processing unit 31 by the clearing information 201 and the path management processing unit will be able to secure a new path from there. When notified to 33 (step S13), the process proceeds to step S8 for determining the number D of paths to be newly secured.

In FIG. 7, when a new path is secured in the communication control device 200 ′, The data stored in the data buffer 36 is transmitted as data 302 from the data transmitting unit 37 to the other communication control device 400 of another node on the newly secured path.

The communication control device 200 'has a routing table 35 for routing data. When a path is set due to a line failure, the contents of the path setting 203 transmitted from the path management processing section 33 to the routing information processing section 31 allow the routing information processing section 31 to execute the routing table 3 5 as necessary. Is rewritten, and the routing information 201 including the content is transmitted to the other node 40.

Referring to FIG. 8, there is shown a communication control device 200 "according to a third embodiment of the present invention. The communication control device 200" is similar to the communication device 200 shown in FIG. Including. The communication control device 200 ′ includes a history storage unit 34. The path management processing unit 33 records, in the history storage unit 34, the cumulative total duration, the cumulative failure occurrence time, and the failure occurrence probability secured for each path in the past as history information. The path management processing unit 33 calculates the required number of newly secured paths D from the history information and sets the path. For example, in a network having a path in which failures frequently occur, the path management processing unit 33 sets a larger value for the number D of paths to be newly secured, and secures many paths at once to improve reliability. Can be enhanced. Further, in a network having a path with few failures, the path management processing unit 33 sets D to a small value in order to minimize the exchange of signaling and the like.

Further, the history storage unit 34 records the duration and failure time secured for each path received from the path management processing unit 33 in chronological order, calculates the failure probability from them, and chronologically records them. It is recorded as a failure history. The path management processing section 33 calculates the number of paths D to be secured which changes in time series from the failure history and sets the paths. As a result, D can be determined based on the characteristics of the failure occurrence rate described in 1 above.For example, during the daytime, D is set to a small value because there are few failures, and at nighttime, many failures occur. By increasing D, the number of paths to be secured can be increased, and a highly reliable network can be obtained.

The communication control device for realizing the communication control method according to the present invention may be a device or a program. The communication control device, the communication control method, and the communication control program according to the present invention may be configured such that, in addition to a network in which a line failure is likely to occur, a failure-prone node or a node using a mobile body frequently changes the form of the renetwork. Even in such a case, it is possible to provide highly reliable communication that can reliably transmit bucket data including important voices and images to the partner node.

Claims

1. A routing information processing unit connected to at least one other node via a communication network;

A routing processor connected to the other node via the communication network, and a path management processing unit connected to the routing information processing unit and the signaling processor;

The first month of Yoro

The routing information processing unit transmits and receives routing information for routing data to and from the other node, and transmits the received routing information to the other node.

of

When a path failure is detected based on the path information, the path information

The path management processing unit holds the minimum number of paths τ to be secured,

Taking into account the failure information, calculate the number R of the currently secured paths, compare the R with the above T, and when R <T, decide to secure a new path, In addition to performing a path setting for newly securing a path, notifying the contents of the path setting to the routing information processing unit, and transmitting a path setting instruction based on the contents of the path setting to the signaling processor. ,

The communication control device, wherein the signaling processor performs signaling with the other node based on the received path setting instruction to newly secure a path set in the path management processing unit.

2. The communication control device according to claim 1, wherein

The number of new passes to be secured is D,

If the maximum number of passes that can be secured is M,

The path management processing unit holds the 0, which is an arbitrary fixed value that satisfies exactly ≤1 ^ + 0≤1 \ / 1, and newly secures the D paths when R <T. The communication control device according to claim 1, wherein the path setting is performed, and the D paths are newly secured.

3. The communication control device according to claim 2,

The path management processing unit is connected to an external device, and outputs T≤R + D≤M from the external device. Communication control characterized by receiving any D satisfying the condition and, when R <T, setting a path for newly securing the D paths and newly securing the D paths. apparatus.

4. The communication control device according to claim 2, wherein

It has a history storage unit,

5. The communication control device according to claim 4, wherein

6. The communication control device according to claim 1, wherein

A routing table connected to the routing information processing section; routing information for performing routing of data received from the other node is recorded in the routing table; The unit rewrites a routing table based on the contents of the path setting received from the path management processing unit, and transmits the routing information to the other node based on the contents of the path setting. Communication control device.

7. The communication control device according to claim 1, wherein

A data buffer, a data receiving unit connected to the other node via a network, and a data transmitting unit,

When the path is newly secured and 0 <R, the data transmission unit transmits the data stored in the data buffer to the other node. Control device.

8. In a communication network in which a link is formed by a plurality of nodes,

A communication control method mounted on the node and setting a path for use in data transmission,

Detecting a failure of the failed path;

A communication control method comprising: performing signaling with the other node based on the contents of the path setting to newly secure the path.

9. The communication control method according to claim 8,

The number of new passes to be secured is D,

If the maximum number of passes that can be secured is M,

Holding the D satisfying D≤R + D≤M, and setting a path for newly securing the D paths when R <T;

A step of newly securing the D paths based on the path setting.

10. The communication control method according to claim 9,

A step of receiving said D satisfying T≤R + D≤M from outside;

When R <T, setting a path for newly securing the D paths and newly securing the D paths based on the path settings are provided. Communication control method.

11. The communication control method according to claim 9, wherein

Calculating the D from the duration and the probability. Characteristic communication control method.

12. The communication control method according to claim 9, wherein

Chronologically recording the reserved duration of the path and the probability that the path has failed;

Calculating the D from the duration and the probability.

13. The communication control method according to claim 8, wherein

A step of transmitting the routing information to another node.

14. The communication control method according to claim 8, wherein

15. A communication control program for realizing the communication control method according to claim 8 by a computer.