Multicast transmission method

• US 6,330,238 B1
• Filed: 10/09/1998
• Issued: 12/11/2001
• Est. Priority Date: 10/31/1997
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Fujitsu Limited
• Inventors: Ooe, Kazuichi
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US09/168,857
• Time in Patent Office: 1,159 Days
• Field of Search: 370/390, 370/312, 370/432
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1854 with non-centralised forwarding system, e.g. chaincast
• CPC Class Codes: H04L 12/1881 with schedule organisation, e.g. priority, sequence management

Abstract

The present invention relates to a multicast transmission method which is capable of realizing a multicast function while maintaining the independence of each of nodes concurrently with minimizing the traffic on a communication network. In the multicast transmission method according to this invention, a data transmitting node, in which a multicast transmission request occurs, adds a multicast address to a data send message and then broadcasts the data send message plus multicast address to all the nodes, while each of the nodes receiving the multicast address refers to its own multicast table to decide whether or not a multicast address coincident with the received multicast address exists in the multicast table. If the same multicast address exists, the node makes a request for the transmission of data responding to the multicast transmission request toward the data transmitting node through the use of a basic communication function, so that the data is transmitted from the data transmitting node to the node making the data transmission request. This invention is applicable to communication networks employing a protocol such as TCP/IP (Transmission Control Protocol/Internet Protocol).

Claims

1. A multicast transmission method of, in a system in which a plurality of nodes are connected through a communication network to each other to be mutually communicable, making a data transmitting node of said plurality of nodes, in which a multicast transmission request occurs, transmit data to a node of said plurality of nodes, which belongs to a specific group, through said communication network,

wherein each of said plurality of nodes includes a communication driver having, as a basic communicating function, a function to issue and send a data send message for sending data to a receive buffer defined in advance in a data receiving node, a data get command for designating data in a memory of a given node to make a request for a transmission of said data to the given node, and a data send command for designating a memory address in a data receiving node to transmit data, and when a node belongs to said specific group, a multicast address designating said specific group is set and registered in a multicast table included in the node belonging to said specific group, and said data transmitting node broadcasts said data send message, to which said multicast address designating said specific group is added, through said communication network to all said plurality of nodes while each of said nodes receiving said multicast address through said data send message refers to its own multicast table to decide whether or not a multicast address coincident with the received multicast address exists within said multicast table, and a node, in which the same multicast address exists within said multicast table, serves as a data receiving node to make a request for a transmission of data corresponding to said multicast transmission request to said data transmitting node through the use of said basic communication function so that said data is transmitted from said data transmitting node to the node serving as said data receiving node.

2. A multicast transmission method as defined in claim 1, wherein said data receiving node, in which said multicast address exists within said multicast table, issues said data get command to said data transmitting node to make a request for transmission of said data corresponding to said multicast transmission request so that said data is transmitted from said data transmitting node to said data receiving node.

3. A multicast transmission method as defined in claim 1, wherein said data receiving node, in which said multicast address exists within said multicast table, sends said data send message to said data transmitting node to make a request for transmission of said data corresponding to said multicast transmission request so that said data is transmitted from said data transmitting node to said data receiving node.

4. A multicast transmission method as defined in claim 1, wherein said data receiving node, in which said multicast address exists within said multicast table, issues said data send command to said data transmitting node to make a request for transmission of said data corresponding to said multicast transmission request so that said data is transmitted from said data transmitting node to said data receiving node.

5. A multicast transmission method as defined in claim 1, wherein said node, in which said multicast address does not exist within said multicast table, issues said data send command to said data transmitting node to inform said data transmitting node of the fact that transmission of said data corresponding to said multicast transmission request is unnecessary.

6. A multicast transmission method as defined in claim 1, wherein said node, in which said multicast address does not exist within said multicast table, issues said data get command to said data transmitting node to inform said data transmitting node of the fact that transmission of said data corresponding to said multicast transmission request is unnecessary.

7. A multicast transmission method as defined in claim 1, wherein said node, in which said multicast address does not exist within said multicast table, sends said data send message to said data transmitting node to inform said data transmitting node of the fact that transmission of said data corresponding to said multicast transmission request is unnecessary.

8. A multicast transmission method as defined in claim 1, wherein said node, in which said multicast address does not exist within said multicast table, immediately terminates its processing without informing said data transmitting node of the fact that transmission of said data corresponding to said multicast transmission request is unnecessary.