JPH11308234A - Method and system for multicast connection in atm network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable saving of a transmission/reception band and a VC management memory and reduction of a multicast connection time by having a cluster member and a multicast server perform conditional operation by using a non- reception flag and a non-transmission flag and setting only a necessary virtual channel. SOLUTION: An ATM network is equipped with a cluster member 101, a MARS 201, a multicast server (MCS) 301 and a switch SW. Then, using a non- reception flag and a non-transmission flag the cluster member 101 and the MCS 301 perform conditional operation and only a necessary virtual channel is set. Here, the cluster member 101 is equipped with a multicast data transmission/reception demand issue means, a multicast data transmission/ reception management means, a multicast data transmission/reception processing means and a multicast data transmission/reception VC control means. Also, the MCS 301 is equipped with a multicast server participation message multicast data transmission/reception processing means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ATM (Asynchronous Trans
fer Mode) A method of performing multicast in a network.

[0002]

2. Description of the Related Art As a system for performing multicast in an ATM (Asynchronous Transfer Mode) network, there are a multicast server (hereinafter, referred to as "MCS") system, an overlay point-to-multipoint connection system (hereinafter, "VC (Virtual Channel)"). ; Virtual channel) mesh method) is known.

In a conventional multicast connection in an ATM network, a MARS_JOIN message (participation message) is used for a Cluster Member to join a multicast group in a reception process. MARS (Multica
The st Address Resolution Server (multicast address resolution server) notifies these messages to all Cluster Members through the cluster control VC (Virtual Channel). Each Cluster Member
Is the MARS_JOI received from MARS through the cluster control VC
See the N message (participation message) and point to Multipoint VC for the corresponding multicast group.
If (one-to-many virtual channels) is set,
Add a leaf.

[0004] In the transmission process, when there is no connection to the destination multicast address of the transmission packet, the transmission node transmits a MARS_REQUEST message to MARS in order to obtain the ATM address of the Cluster Member belonging to the multicast group. MARS
Checks if an entry exists for the target multicast address, and if not, MARS
Returns _NAK. In this case, the transmitting node discards the transmission packet for the multicast address. On the other hand, if the entry for the target multicast address is
If registered in MARS: ・ If MCS does not exist, notify the ATM addresses of all Cluster Members participating in the group in MARS_MULTI message. -If an MCS exists, the ATM addresses of all MCSs supporting the group are notified in the MARS_MULTI message.

[0005] When the Cluster Member receives MARS_MULTI, the Cluster Member sends P to all ATM addresses contained in the message.
Set up an oint to Multipoint connection. This will send a multicast packet to the MCS if one exists.

As a related prior art, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 64881/1994 discloses a "method and apparatus for confirming a multicast connection state" in a case where a multicast fixed connection communication is performed in a relay type network service such as a frame relay or a cell relay. By defining and transferring a connection status notification message obtained by editing the above status information, it is possible to confirm a connection status such as disconnection of a multicast destination link connection. Also, “Packet transmitting node device and packet transfer method” described in JP-A-9-64915
Is that a plurality of output virtual connections including a point-multipoint connection can be used for one multicast address, so that different service qualities can be provided for each receiver.
Further, the "multicast routing method and system" described in Japanese Patent Application Laid-Open No. 9-284275 discloses a hierarchical multicast routing method and system at various levels by configuring routing nodes in a hierarchical structure having a vertical relationship. To provide.

[0007]

However, the first problem is to be solved.
In the case of the MCS method, the traffic is concentrated on the MCS, thereby lowering the throughput. Further, since the data needs to be reassembled, there is an end-to-end delay. However, in the case of the VC mesh, there is no point where traffic concentrates, so high performance can be obtained.

[0008] Second, in the case of the MCS system, when a transmitting node belongs to the same multicast group, it receives a packet transmitted by itself.

Third, in the case of the VC mesh method, a Point to Multip
Since an oint VC is set, each member needs to set the number of receiving VCs by the number of transmitting nodes, and uses a large amount of resources necessary for the VC. In the MCS method, each group member is M
It only terminates the Point to Multipoint VC from the CS, and can effectively use the resources of the VC.

[0010] Fourth, in the case of the VC mesh method, when the members of the multicast group change, all the transmitting nodes add and delete leaves, so that it takes time until the change in members is reflected. In the MCS method, the time required for updating the connection is short because only the MCS needs to add or delete a leaf.

It is an object of the present invention to provide a multicast system in an ATM network which can save transmission / reception bandwidth, save VC management memory on machines and switches, and shorten Multicast connection time.

[0012]

According to the present invention, there is provided a multicast connection method in an ATM network, wherein when a cluster member requests only multicast transmission, a non-transmission flag having a false logical value and a non-receiving flag having a true logical value are provided. Is transmitted to the multicast address resolution server, and a MARS_JOIN message including a non-transmission flag whose logical value is false and a non-reception flag whose logical value is true is sent to the multicast address resolution server to request only the reception of the multicast. Contains a true non-transmission flag and a non-reception flag whose logical value is false.
Sending a JOIN message to a multicast address resolution server, wherein the multicast address resolution server determines if there is a multicast server that supports the target multicast group of the MARS_JOIN message received from the cluster member;
Sending an IN message to the multicast server, sending a MARS_JOIN message including the ATM address of the multicast server to the cluster member, and receiving a MARS received from the cluster member.
_JOIN message target multicast
Said M received by all group members when there is no multicast server supporting the group
Sending an ARS_JOIN message; and, when the cluster member receives the MARS_JOIN message, when there is no multicast server supporting the target multicast group, the cluster member corresponds to the multicast address with respect to all multicast addresses. Setting a point-to-multipoint for an address contained in the MARS_JOIN message only when the non-reception flag is false, and the multicast server receiving the MARS_SJOIN Adding a receiving node to the leaf only when the non-receiving flag in the message is false; The server sends a MARS_MULTI message of the information addition of the multicast server to the cluster member when the multicast server supporting the target multicast group of the MARS_REQUEST message received from the cluster member exists to the cluster member. When there is no such multicast server supporting the target multicast group of the MARS_REQUEST message received from the member,
MA containing address of group member and transmission / reception information
Transmitting an RS_MULTI message; and setting a point-to-point virtual channel for a member of the group when the cluster member receives the MARS_MULTI message.

[0013] In the multicast connection system in the ATM network according to the present invention, when only transmission of multicast is requested, MARS_REQUEST including a non-transmission flag having a false logical value and a non-receiving flag having a true logical value is provided.
When transmitting a message and a MARS_JOIN message including a non-transmission flag with a logical value of false and a non-reception flag with a logical value of true to the multicast address resolution server and requesting only multicast reception,
Means for transmitting a MARS_JOIN message including a non-transmission flag having a true logical value and a non-receiving flag having a false logical value to the multicast address resolution server; and a target multicast group when the MARS_JOIN message is received. When there is no multicast server to support, for all multicast addresses, only when the non-receiving flag corresponding to the multicast address is false,
Means for setting a point-to-multipoint for the address contained in the MARS_JOIN message; means for setting a point-to-point virtual channel for the members of the group upon receiving the MARS_MULTI message; And a MARS received from said cluster member
_JOIN message target multicast
When there is a multicast server supporting the group, a MARS_SJOIN message is sent to the multicast server, and a MARS_JOIN message containing the ATM address of the multicast server is sent to the cluster member and received from the cluster member. Means for transmitting the MARS_JOIN message received to all group members when there is no multicast server supporting the target multicast group of the MARS_JOIN message; and a target for the MARS_REQUEST message received from the cluster member.
When a multicast server supporting a multicast group is present, send a MARS_MULTI message with the information of the multicast server to the cluster member, and support a target multicast group of a MARS_REQUEST message received from the cluster member. MARS_MULTI containing group member addresses and send / receive information when there is no multicast server
Means for transmitting a message, a multicast address resolution server, and the M address received from the multicast address resolution server.
A multicast server having means for adding a receiving node to a leaf only when the non-receiving flag in the ARS_SJOIN message is false.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
FIG. 3 is a diagram illustrating a configuration of an M network. In the figure, ATM
Network is Cluster Member101, MARS201,
An MCS 301 and a switch (SW) are provided.

Referring to FIG. 1, Cluster Member 101
Is a Multicast data transmission / reception request issuing means 102 for designating only transmission or reception of Multicast data from an application, and for receiving a Multicast data transmission / reception request issuance and managing that there is designation of only Multicast data transmission or reception. The Multicast data transmission / reception management means 103 receives the Multicast data transmission / reception request recognition result, and
Multicast data transmission / reception processing means 104 for processing “transmission / non-transmission” and “reception / non-reception” of icast data, and control of transmission VC and reception VC of Multicast data by Multicast data transmission / reception processing means 104 Data transmission / reception VC control means 105 for transmitting data.

Referring to FIG. 2, MARS (Multicast Addre
The ss Resolution Server 201 includes a MARS_JOIN message Multicast data transmission / reception information notification unit 202 for receiving the MARS_JOIN message and notifying the transmission / reception information of the Multicast data.

Referring to FIG. 3, an MCS (Multicast Server)
r) 301 is a Multica server for processing transmission and reception of Multicast data in response to the Multicast Server participation message.
st Server participation message Multicast data transmission / reception processing means 302 is provided.

The above Cluster Member 101 and MARS 201
With the configuration of the MCS 301 and the MCS 301, it is possible to limit the establishment of a VC, thereby saving transmission / reception bandwidth, saving VC management memory on machines and switches, and shortening Multicast connection time.

Next, the operation of the present embodiment will be described in detail with reference to the flowcharts of FIGS.

Here, an operation of the ATM Multicast connection system of the present embodiment for performing only reception of Multicast data will be described.

First, the Multicast data transmission / reception request issuing means 102 generates a request for receiving Multicast data. At this time, the Multicast NO TX flag is set to “1” to request that only the Multicast DATA be received, and the Multicast NO RX
The flag is set to "0" and a request is issued (step S5).
01).

Note that the multicast data transmission / reception request issuing means 102 is actually executed by an application. At this time, as a means for setting the transmission / reception flag, a method of directly setting from an application or a case of setting in advance by an ATM network setting application is conceivable.

In response, the Multicast_data transmission / reception managing means 103 creates a Multicast participation message (step S502).

Further, the multicast data transmission / reception management means 10
3 is a Multicast Add corresponding to the requested Multicast Address
A Multicast transmission / reception management flag is generated for managing data transmission / reception for each resource, and the request content is copied (step S503).

Next, the multicast data transmission / reception processing means 10
4 judges whether the Multicast NO RX flag is "1" (step S504), and determines whether the Multicast NO RX flag is "1".
0 ", so the Multicast join message
NO RX flag is set to "0" and added (step S50)
5). Subsequent to step S505, the Multicast data transmission / reception processing means 104 determines whether or not the Multicast NO TX flag is "1" (step S507).
When the NO TX flag is not "1", the Multicast NO TX flag is set to "0" and added to the Multicast participation message (step S508). When the Multicast NO TX flag is “1”, the Multicast NO TX f
The lag is set to "1" and added (step S509).

After step 508, step S50
9 and step S511 are executed. Step 510
After, step 511 is executed.

At step 509, the Multicast data transmission / reception processing means 104 sends the Multicast participation message to the MARS_
Copy to REQUEST message and send MARS_REQUEST message to MARS.

In step S511, the Multicast data transmission / reception processing means 104 sends the Multicast participation message to the MAR
Copy S_JOIN message and MARS_JOIN message to M
Send to ARS.

Referring to FIG. 6, upon receiving the MARS_JOIN message (step S601), MARS determines whether there is an MCS supporting the target multicast group (step S602). If there is an MCS that supports the target multicast group, a MARS_SJOIN message is transmitted to the MCS (step S604), the ATM address of the MCS is put in the MARS_JOIN message, and the MURS_JOIN message is sent to the Cluster Mem.
ber is notified (step S603). Step S60
In 2, if there is no MCS supporting the target multicast group, the received MARS_JOIN
MARS_J Copy of message to all group members
It is transmitted as an OIN message (step S603).

When the Cluster Member receives the MARS_JOIN message (step S605), if an MCS supporting the target multicast group exists, the Multicast transmission system processing is completed (step S61).
0). If there is no MCS that supports the target multicast group, the corresponding Multicast Addr
Multicast NO RX fla of transmission / reception management flag corresponding to ess
It is determined whether g is "1" (step S60).
7). If the Multicast NO RX flag of the transmission / reception management flag corresponding to the corresponding Multicast Address is not "1", the address included in the message is pointed to.
A Multipoint is set (step S608), and it is checked whether or not the processing has been performed on all the notified Multicast Addresses (step S609). If not, the unprocessed Multicast Addr is started from S607.
Execute for ess. If processing is completed, Multica
The st transmission system processing is completed (step S610). In step S607, if the Multicast NO RX flag of the transmission / reception management flag corresponding to the corresponding Multicast Address is "1", it is checked whether or not processing has been performed for all the notified Multicast Addresses ( Step S609) If it has not been performed, the process is executed from S607 on the unprocessed Multicast Address. If the processing has been completed, the Multicast transmission system processing is completed (step S610).

The "applicable" in step S607 is as follows.
When the application is requested by the multicast data transmission / reception request issuing means 102, the Multicast Ad
This refers to the management structure of the Multicast Address created for managing the Multicast transmission / reception flag associated with the dress.

When the MCS receives the MARS_JOIN message (step S611), the MulticastServer participation message Multicast data transmission / reception processing means 302
It is determined whether the NO RX flag is "1" (step S612). If the Multicast NO RX flag is not "1", the receiving node is added to the leaf (step S61).
3), end of Multicast participation reception (step S61)
4). In step S612, the Multicast NO RX flag is "
If it is 1 ", the reception of the Multicast participation is ended (step S614).

Next, an operation of transmitting only Multicast data will be described.

First, a multicast data transmission request is issued by the multicast data transmission / reception request issuing means 102. At this time, the Multicast NO TX flag is set to “0” to request that only the transmission request of Multicast data be performed, and the Multicast NO R
A request is issued with the X flag set to "1" (step S
501).

In response, the multicast data transmission / reception management means 103 creates a MARS_JOIN message (step S502).

Further, the multicast data transmission / reception management means 10
3 is the Mul associated with the Multicast Address inside the network driver corresponding to the requested Multicast Address.
A ticast transmission / reception management flag is generated, and the content of the request is copied (step S503).

Next, the multicast data transmission / reception processing means 10
4 judges whether the Multicast NO RX flag is "1" (step S504), and determines whether the Multicast NO RX flag is "1".
1 ", so the Multicast join message
NO RX flag is set to "1" and added (step S50)
6).

After step S506, Multicast data
The transmission / reception processing means 104 sets the Multicast NO TX flag to "1"
Is determined (step S507), and the Multic
Since the astNO TX flag is not “1”, the Multicast NO TX flag is set to “0” and added to the Multicast participation message (step S508).

After step 508, step S50
9 and step S511 are executed. Step 510
After, step 511 is executed.

At step 509, the Multicast data transmission / reception processing means 104 transmits the Multicast participation message to the MARS_
Copy to REQUEST message and send MARS_REQUEST message to MARS.

In step S511, the Multicast data transmission / reception processing means 104 sends the Multicast participation message to the MAR
Copy S_JOIN message and MARS_JOIN message to M
Send to ARS.

The operation following step S511 has already been described with reference to FIG. 6, and a duplicate description will be omitted.

Referring to FIG. 7, after step S509, MARS receives the MARS_REQUEST message from the Cluster Member (step S701).

In response, MARS determines whether there is an MCS supporting the target multicast group (step S702). If there is an MCS that supports the target multicast group, a MARS_MULTI message with the address information of the MCS added is generated (step S703), and step S70 is performed.
Go to 5. If there is no MCS supporting the target multicast group in step S702, a MARS_MULTI message including the group member address and transmission / reception information is generated (step S70).
4), proceed to step S705. In step S705, a MARS_MULTI message is transmitted to the Cluster Member.

Referring to FIG. 8, the Cluster Member receiving the MARS_MULTI message (step S801) sets a Point-to-Multipoint VC to the group members (step S802).

[0046]

As described above, according to the present invention,
Since only necessary VCs can be specified to be set, transmission / reception bandwidth can be saved, VC management memory on machines and switches can be saved, and Multicast connection time can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a Cluster Member according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of MARS according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of an MCS according to an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an ATM network according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of a Cluster Member according to the embodiment of the present invention.

FIG. 6 shows MARS, MCS and Cluster according to an embodiment of the present invention.
5 is a flowchart for explaining the operation of a Member.

FIG. 7 shows MARS and Cluster Memb according to an embodiment of the present invention.
6 is a flowchart for explaining the operation of er.

FIG. 8 is a flowchart illustrating an operation of a Cluster Member when receiving a MARS_MULTI message according to an embodiment of the present invention.

[Explanation of symbols]

101 Cluster Member 102 Multicast data transmission / reception request issuing means 103 Multicast data transmission / reception management means 104 Multicast data transmission / reception processing means 105 Multicast data transmission / reception VC control means 201 MARS (Multicast Address Resolution Server;
Multicast address resolution server) 301 MCS (Multicast Server)

Claims (2)

[Claims] When a cluster member requests only multicast transmission, a MARS_REQU including a non-transmission flag with a logical value of false and a non-reception flag with a logical value of true is provided.
When transmitting an EST message and a MARS_JOIN message including a non-transmission flag having a false logical value and a non-receiving flag having a true logical value to the multicast address resolution server and requesting only multicast reception, the logical value becomes true. Sending a MARS_JOIN message including a non-transmission flag and a non-reception flag whose logical value is false to the multicast address resolution server; and the multicast address resolution server performs a target multicast of the MARS_JOIN message received from the cluster member. M when there is a multicast server supporting the group
The ARS_SJOIN message is sent to the multicast
Sending to the server, the AT of the multicast server
Sending a MARS_JOIN message including the M address to the cluster member, and when there is no multicast server supporting the target multicast group of the MARS_JOIN message received from the cluster member, the MARS_JOIN received by all group members. Sending a message, when the cluster member receives the MARS_JOIN message,
When there is no multicast server supporting the group, for all multicast addresses,
Setting a point-to-multipoint for an address contained in the MARS_JOIN message only when a non-receiving flag corresponding to the multicast address is false; The MARS_S received from the server
Adding a receiving node to the leaf only when the non-receiving flag in the JOIN message is false; and the multicast address resolution server receiving the MARS_REQ received from the cluster member.
Sending a MARS_MULTI message with the information of the multicast server to the cluster member when the multicast server supporting the target multicast group of the UEST message is present;
Transmitting a MARS_MULTI message containing the address of group members and transmission / reception information when the multicast server supporting the target multicast group of the _REQUEST message does not exist; and the cluster member has received the MARS_MULTI message. Setting a point-to-point virtual channel for members of the group at times. 2. When requesting only multicast transmission, a MARS_REQUEST message including a non-transmission flag having a false logical value and a non-reception flag having a true logical value, and a non-transmission flag having a false logical value and a logical value being true. When sending a MARS_JOIN message including a non-reception flag to the multicast address resolution server and requesting only multicast reception, a MA including a non-transmission flag whose logical value is true and a non-reception flag whose logical value is false
Means for transmitting an RS_JOIN message to the multicast address resolution server;
When receiving the RS_JOIN message, when there is no multicast server supporting the target multicast group, and when the non-receiving flag corresponding to the multicast address is false for all multicast addresses, the MARS
Means for setting point-to-multipoint for the address contained in the _JOIN message;
Means for setting up a point-to-point virtual channel for members of the group upon receipt of the RS_MULTI message; and supporting a target multicast group of MARS_JOIN messages received from said cluster members. When a multicast server exists,
Send a MARS_SJOIN message to the multicast server and send the multicast server ATM
Sending a MARS_JOIN message including the address to the cluster member, and transmitting a MARS_JOIN message received from the cluster member to the target
Means for transmitting the MARS_JOIN message received to all group members when there is no multicast server supporting the multicast group, and MARS_JOIN received from the cluster member.
When there is a multicast server supporting the target multicast group of the REQUEST message, a MARS_MULTI message with information of the multicast server is transmitted to the cluster member, and the MAR received from the cluster member is transmitted.
Means for transmitting a MARS_MULTI message containing the address of group members and transmission / reception information when there is no multicast server supporting the target multicast group of the S_REQUEST message; A multicast server having means for adding a receiving node to a leaf only when the non-receiving flag in the MARS_SJOIN message received from the address resolution server is false, comprising: a multicast connection in an ATM network. method.