KR100375515B1 - Method for assigning multiple multicasting servers for group communication in ATM network - Google Patents

Abstract

The present invention relates to a multi-casting server allocation method for group communication in an ATM network. Reading information of topology information G (V, E) including topology information of ATM network, set M of multiple multicasting servers MCS, data receiver S, data sender N (S1) ; Determining an Mindex having a minimum shortest path between the data receiver N and each MCS included in the multiple MCS list M, and obtaining a minimum path value MINdelay (S2); Shortest path ShortestPath (S, Mindex) between data sender (S) and Mindex, the shortest path multicast server, and shortest path ShortestPath (Mindex, N) between Mindex and receiver (N) Obtaining Cx for checking presence (S3); Checking whether Cx = 0 (S4) and if Cx = 0, there is no duplicate path, and delivering Mindex, which is an identifier of the MCS determined for the data receiver N, to the data receiver N (S5). ; If Cx is not 0, there is a redundant path, and instead of the Mindex previously determined as the MCS for the data receiver N, the data sender S is responsible for the multicaster data transmission and thus the shortest distance between the data sender S and the receiver N. Obtaining a path value TOTALdelay (S6); And transferring the identifier of the sender D to the data receiver N as a multicasting server determined for the receiver N (S7).

Description

Method for assigning multiple multicasting servers for group communication in ATM network

The present invention relates to a method for allocating multiple multicasting servers for group communication in an asynchronous transmission mode network. In particular, when providing an Internet service of group communication using an IP multicast address in an ATM network, a plurality of multicasting servers are provided. The present invention relates to a method for allocating a multicasting server for group communication in an asynchronous transmission mode network to reduce traffic of an ATM network and to reduce data propagation delay between sender and receiving group members.

In general, a system using a single multicasting server for conventional group communication has a single multicasting server (MCS), a sender (S1 to S4), and a multicast group (G1 to G4) as shown in FIG. ), And the destination address of the data (d = G1 to d = G4).

Referring to FIG. 1, each sender S1 to S4 first delivers data to a specific multicast group G1 to G4 to a single multicasting server MCS. The single multicasting server delivers the received multicast data to the members of the corresponding multicast group G1 to G4 according to the destination group (d = G1 to d = G4).

However, in the past, the implementation of a multicast support method using a single multicasting server was common, but this scheme is likely to be a bottleneck in a single multicasting server, and if a single multicasting server fails, multicasting is performed. There is a disadvantage that the delivery of traffic is difficult. In addition, the existing scheme has a disadvantage in that the data propagation delay between the sender and the plurality of group members cannot be minimized. Finally, part of the data transfer path formed between the sender and the plurality of group members has a problem that the traffic increases through the inflow of unnecessary traffic.

The present invention has been proposed to solve the problems of the prior art, and an object of the present invention is to overcome the shortcomings of a single multicasting server (MCS) for group communication using an IP multicast address. By reducing the end-to-end propagation delay by optimizing the propagation path formed between sender and receiving group members for group communication using Provides a multi-casting server allocation method for group communication in an asynchronous transmission mode network to prevent the inflow of traffic on unnecessary paths.

1 is a conceptual diagram using a single multicasting server for a conventional group communication.

2 is a conceptual diagram using multiple multicasting servers for group communication.

3A to 3B are two exemplary diagrams for practicing the present invention.

4A is a flowchart illustrating a multi-casting server allocation method for group communication in an ATM network according to a first embodiment of the present invention.

4B is a flowchart illustrating a multi-casting server allocation method for group communication in an ATM network according to a second embodiment of the present invention.

5 is a system configuration diagram illustrating a multi-casting server allocation method for group communication in an ATM network in a client / server concept.

6 is a conceptual diagram illustrating main operations between a group member (client) and a server.

Explanation of symbols on the main parts of the drawings

M1 to Mn: Identifier of the multicasting server (MCS) S: Data sender

r1: data receiver as a group member of a specific multicast group

Pa, b: Path delay from node a to node b

CX: Crossover Switch (ATM Switch), which is the starting path of the redundant path between the data sender (S)-MCS (Mr)-data receiver (r1)

In order to achieve the above object, the present invention is applied to a system having a plurality of multicasting server (MCS) for group communication by IP multicast in an asynchronous transmission mode (ATM) network, ATM as the initial input data Reading information of topology information G (V, E) including topology information of a network, a set M of multiple multicasting servers MCS, a data receiver S, and a data sender N (S1); Determining an address for an optimal multicasting server and obtaining a minimum path value for the determined multicasting server (S2); Obtaining a node that is a crossover switch corresponding to a starting point of a redundant path (S3); Transmitting (S5) an identifier of a multicasting server determined for a data receiver (N) to the data receiver (N); Obtaining a shortest path value between the data sender S and the data receiver N (S6); And a step (S7) of transmitting the identifier (including the ATM address) of the sender S to the data receiver N as the multicasting server determined for the data receiver N, including the group in the asynchronous transmission mode method. In the multi-casting server allocation method for communication, in step S2, the shortest distance path between the data receiver (N) and each multicasting server included in the multi-multicasting server (MCS) set (M) is calculated through the shortest distance path. The index number of one multicasting server having a distance path is determined to determine an address (Mindex) for the optimal multicasting server, the minimum path value for the determined multicasting server is obtained, and in step S3, the data sender S ) And the shortest path (ShortestPath (S, Midex)} between the address (Midex), the multicasting server with the shortest path, and the address (Mindex) and data receiver ( N) Checks whether there is a duplicate path between the shortest paths {ShortestPath (Mindex, N)}, and if there is a duplicate path, the node {Cx = DetectDuplicatePath (S, Midex, N)}, and in the step S5, it is checked whether the node Cx obtained in the step S3 is 0 (S4). If the node Cx is 0, the duplicate path does not exist. The address Mindex, which is an identifier of the multicasting server determined for the data receiver N, is transmitted to the data receiver N. In step S6, if the node Cx obtained in step S3 is not 0, a redundant path is generated. If present, the data sender S is responsible for multicast data transmission instead of the determined address Mindex as the multicasting server for the data receiver N, so that the data sender S and the data receiver ( A multi-casting server allocation method for group communication in an asynchronous transmission mode network characterized in that the shortest path value between N) is obtained.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, in order to describe a multicasting server (MCS) system for group communication, multiple multicasting servers M1 to Mn, senders S1 to S4, and multicast groups ( G1 to G4), destination addresses of data (d = G1 to d = G4), and the like.

When the data senders S1 to S4 that are the sending clients request a connection to the corresponding multicasting servers M1, M2, and M3 distributed with the corresponding destination group address information for group communication, the multicasting server Send data to the destination group address of the receiving client. Hereinafter, a data sender and a data receiver mean a sending client and a receiving client.

3A to 3B are two exemplary views for practicing the present invention.

Referring to FIGS. 3A and 4A, when a node r1 as a data receiver wants to join a specific multicast group, an optimal multicasting server (MCS) selection for multicasting for group communication to node r1 is as follows. Follow the rules of

First, one multicasting server (MCS) Mr having the shortest distance path is selected in calculating the shortest distance path between the data receiver r1 and each of the multicasting servers.

Second, the overlapping path between the shortest distance path (SPS, Mr) between the data sender (S) and the multicasting server (Mr) and the shortest distance path (SPMr, r1) between the multicasting server (Mr) and the data receiver (r1) If present, the node Cx, which is a Crossover Switch (ATM exchange), which is the start node of the redundant path is obtained.

Third, the corresponding multicasting server (MCS = MIN [(SPr1, Mr + SPMr, s), SPr1, S] by one MCS index number (ATM address) having a minimum shortest path to be multicasted to node r1. Find the index of MCS with.

3B and 4B, when a node r1 wants to join a specific multicast group, the selection of an optimal multicasting server (MCS) for multicasting to the node r1 follows the following rule.

First, select one multicasting server (MCS) Mr having the shortest distance path. The overlapping path between the shortest distance path (SPS, Mr) between the data sender (S) and the multicasting server (Mr) and the shortest distance path (SPMr, r1) between the multicasting server (Mr) and the data receiver (r1) exists. In this case, node Cx, which is a crossover switch (ATM exchange), which is a start node of a redundant path, is obtained.

Third, the corresponding multicasting server (MCS = MIN [(SPr1, Mr + SPMr, S), SPr1, S] by one MCS index number (ATM address) having the minimum shortest path to be multicasted to node r1. Find the index of MCS with.

4A is a flowchart illustrating a multi-casting server allocation method for group communication in an ATM network according to a first embodiment of the present invention.

Topology information (G (V, E)) including topology information of ATM network which is initial input data, set (M) of multiple multicasting servers (MCS), data receiver (S), and data sender (N) The information is read (step S1).

Topology information of ATM network G (V, E): V = V1, ..., Vn, E = (a, b) | a, b V

(Node information of V: ATM switch, E: line between ATM switch and exchange)

Set of multiple MCS M = M1, ..., Mk

Recipient (corresponds to the desired node to join the group) = N, N V

The index number of one MCS having the shortest shortest path is obtained by calculating the shortest path between the data receiver (N) and each MCS included in the multi-casting server (MCS) list M, and the Mindex is determined as the optimal MCS. At this time, the minimum path value MINdelay is obtained (step S2).

MINdelay = MIN [ShortestPathDelay (N, M1), ShortestPathDelay (N, M2), ...,

ShortestPathDelay (N, Mk)]

Index = INDEX (MIN [ShortestPath (N, M1), ShortestPath (N, M2), ...,

ShortestPath (N, Mk)])

MCS = Mindex

The shortest path ShortestPath (S, Mindex) between the data sender (S) and Mindex, the multicasting server with the shortest path, and the shortest path ShortestPath (Mindex, N) between Mindex and receiver (N) It is checked whether the path exists (step S3).

If duplicate paths exist, Cx = DetectDuplicatePath (S, Mindex, N), which is a crossover switch (ATM exchange) corresponding to the starting point of the redundant path, is obtained.

It is checked whether Cx = 0 (step S4), and if Cx = 0, no duplicate path exists, and Mindex, which is an identifier of the MCS determined for the data receiver N, is transmitted to the data receiver N (step S4). S5).

If Cx has a nonzero value, there is a redundant path, and instead of Mindex previously determined as the MCS for the data receiver N, the data sender S is responsible (i.e., the sender S is a multicaster to the receiver N). The shortest path value TOTALdelay between the data sender S and the receiver N is obtained (step S6).

As the multicasting server determined for the data receiver N, an identifier (including an ATM address) of the sender D is transmitted to the data receiver N (step S7).

4B is a flowchart illustrating a multi-casting server allocation method for group communication in an ATM network according to a second embodiment of the present invention.

Topology information (G (V, E)) including topology information of ATM network which is initial input data, set (M) of multiple multicasting servers (MCS), data receiver (S), and data sender (N) The information is read (step S9).

Topology information of ATM network G (V, E): V = V1, ..., Vn, E = (a, b) | a, b V

(V: node information of ATM switch, E: line between ATM switch and exchange)

Set of multiple MCS M = M1, ..., Mk

Recipient (corresponds to the desired node to join the group) = N, N V

The index number of one MCS having the shortest shortest path is obtained by calculating the shortest path between the data receiver (N) and each MCS included in the multi-casting server (MCS) list M to determine the Mindex as the optimal MCS. In this case, MINdelay, which is the minimum path value, is obtained (step S10).

MINdelay = MIN [ShortestPathDelay (N, M1), ShortestPathDelay (M1 + S),

ShortestPathDelay (N, M2), ShortestPathDelay (M2 + S),

:

ShortestPathDelay (N, Mk), ShortestPathDelay (Mk + S)]

Index = INDEX [MIN [ShortestPathDelay (N, M1), ShortestPathDelay (M1 + S),

ShortestPathDelay (N, M2), ShortestPathDelay (M2 + S),

:

ShortestPathDelay (N, Mk), ShortestPathDelay (Mk + S)]]

MCS = Mindex

Shortest path ShortestPath (S, Mindex) between the data sender S and Mindex which is the multicasting server MCS having the shortest path, and Shortest path ShortestPath (Mindex, N) between Mindex and receiver (N) Check for duplicate paths in between. If there is a redundant path, Cx = DetectDuplicatePath (S, Mindex, N), which is a crossover switch (ATM exchange) corresponding to the starting point of the redundant path, is obtained (step S11). It is checked whether Cx = 0 (step S12). If Cx = 0, a duplicate path does not exist, and Mindex, which is an identifier of the MCS determined for the data receiver N, is transmitted to the data receiver N (step S12). S13).

If Cx has a non-zero value, a duplicate path exists and instead of the Mindex previously determined as the MCS for the data receiver N, the data sender S is responsible for multicast data transmission (i.e., the sender S The receiver N is responsible for multicast data transmission. The shortest path value TOTALdelay between the data sender S and the receiver N is obtained (step S14).

As the multicasting server determined for the data receiver N, an identifier (including an ATM address) of the sender D is transmitted to the data receiver N (step S15).

5 is a system configuration diagram illustrating a multi-casting server allocation method for group communication in an ATM network in a client / server concept.

After allocating Mindex, which is the optimal MCS to handle multicasting data processing of the client N, among the multiple MCSs at the sending client N, the multicast data is sent to the same group members at the sending client N for the client N. When sent to Mindex, which is a selected MCS, it is sent to a set of group members (clients) belonging to the same group as client N in Mindex.

Multicast data of another client belonging to the same group is received from the group member belonging to the same group as the client N via the Mindex.

6 is a conceptual diagram illustrating main operations between a group member (client) and a server. The client area has a subscription group address (g) and the data sender's own address (N), and in the MCS allocation server area existing as a software module embedded in a hardware board in a computer or an ATM switch, the group in the ATM network Data receiver N, which is a client, including MCS allocation function, subscription group address (g), multiple MCS set (M), subscriber client address (N) applied with multiple multicasting server allocation methods for communication (method 1 and method 2) Method 1 and method 2 are selectively performed to allocate the MCS for the client, and the Mindex, which is the optimal MCS address, is delivered to the client as the final value of the calculation.

Therefore, in group communication using IP multicast address in ATM network, an optimal multicasting server is allocated among multiple multicasting servers to reduce data propagation delay between sender and receiver group members, and sender and receiver group members. By optimizing the data transmission path between them, it is possible to reduce data inflow into unnecessary paths, thereby improving network performance.

As described above, the method for allocating multiple multicasting servers for group communication in an ATM network according to the present invention includes multiple multicasting servers in data transmission via multiple multicasting servers (MCS) in group communication using an IP multicast address. Among them, the optimal multicasting server can be assigned to reduce data propagation delay between sender and receiving group members, and the data delivery path between sender and receiving group members is optimized in data passing through multiple multicasting servers. By reducing data inflow into unnecessary paths, network performance can be improved, and when developing a multicasting platform using multiple multicasting servers, it can be used as an optimal multicasting selection method.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (2)

In order to apply to a system having a plurality of multicasting server (MCS) for group communication by IP multicast in an asynchronous transmission mode (ATM) network, Reads topological information {G (V, E)} including topology information of ATM network which is initial input data, set M of multiple multicasting servers MCS, data receiver S and data sender N Step S1; Determining an address for an optimal multicasting server and obtaining a minimum path value for the determined multicasting server (S2); Obtaining a node that is a crossover switch corresponding to a starting point of a redundant path (S3); Transmitting (S5) an identifier of a multicasting server determined for a data receiver (N) to the data receiver (N); Obtaining a shortest path value between the data sender S and the data receiver N (S6); And In a group communication in the asynchronous transmission mode method comprising the step (S7) of transmitting the identifier (including the ATM address) of the sender S to the data receiver N as the multicasting server determined for the data receiver N. In the multi-casting server allocation method for In the step S2, the index number of one multicasting server having the smallest shortest path through calculation of the shortest distance path between the data receiver N and each multicasting server included in the multicasting server (MCS) set (M). Determining the optimal multicasting server address (Mindex), to obtain the minimum path value for the determined multicasting server, In the step S3, the shortest path (ShortestPath (S, Midex)) between the data sender S and the address Midex, which is a multicasting server having the shortest path, and between the address Mindex and the data receiver N It checks whether there is a duplicate path between the shortest paths {ShortestPath (Mindex, N)} and if there is a duplicate path, the node {Cx = DetectDuplicatePath (S, Midex, N), which is the crossover switch corresponding to the starting point of the duplicate path. } In step S5, it is checked whether the node Cx obtained in step S3 is 0 (S4). If the node Cx is 0 as a result of the check, a duplicate path does not exist for the data receiver N. Delivering the address (Mindex), the identifier of the determined multicasting server to the data receiver (N), In the step S6, if the node Cx obtained in the step S3 is not 0, a redundant path exists, and as a multicasting server for the data receiver N, the data sender S instead of the determined address Mindex. The multicasting server allocation method for group communication in the asynchronous transmission mode network, characterized in that the multicast data transmission to obtain the shortest path value between the data sender (S) and the data receiver (N). delete