Multicast packet distribution method, system, address structure of packet and mobile station

A multicast packet distribution system for distributing a packet from an origination host to a destination host belonging to a multicast group via communication nodes in a packet communication network that includes a plurality of domains, each said communication node in said multicast packet distribution system comprising:

• a node determination part for determining whether said communication node is an outside node positioned outside said domain, or an inside node positioned inside said domain, or a boundary node positioned between the inside and the outside of said domain when said communication node receives said packet;
• an outside node distribution part for transferring said packet to said domain according to a unicast routing procedure when said communication node determines itself to be said outside node;
• a boundary node distribution part for transferring said packet to said multicast group according to a multicast routing procedure when said communication node determines itself to be said boundary node;
• and
• an inside node distribution part for transferring said packet received according to a multicast routing procedure to said multicast group according to a multicast routing procedure when said communication node determines itself to be said inside node.

An address structure of a packet used in a multicast packet distribution method used for distributing a packet from an origination host to a destination host belonging to a multicast group via communication nodes in a packet communication network that includes a plurality of domains, said address structure comprising:

• a domain address for specifying a domain;
• a group address for identifying a group of said destination host;
• and
• an identifier for indicating that said domain address and said group address can be used.

A mobile station that receives a packet multicasted according to a multicast packet distribution method used for distributing a packet from an origination host to said mobile station belonging to a multicast group via communication nodes in a packet communication network that includes a plurality of domains, said multicast packet distribution method comprising the steps of:

• sending a packet to a multicast group in a domain from said origination host;
• transferring said packet to said domain via a communication node in the outside of said domain according to a unicast routing procedure;
• and
• wherein, when a predetermined communication node in said domain receives said packet, said predetermined communication node transfers said packet to said mobile station according to a multicast routing procedure, and said packet includes a domain division multicast address having a domain address for specifying said domain and a group address for identifying a group of said mobile station;
• said mobile station comprising:
• a group registration part for registering said group address;
• a domain obtaining part for obtaining said domain address that specifies a domain to which a communication node for said mobile station belongs from said communication node for said mobile station;
• a multicast address generation part for generating a multicast address by combining said domain address and said group address;
• a sending part for sending said multicast address to said communication node for said mobile station;
• wherein said communication node for said mobile station transfers said packet to said mobile station by using said multicast address.

A mobile station that receives a packet multicasted according to a multicast packet distribution method used for distributing a packet from an origination host to said mobile station belonging to a multicast group via communication nodes in a packet communication network that includes a plurality of domains, said multicast packet distribution method comprising the steps of:

• sending a packet to a multicast group in a domain from said origination host;
• transferring said packet to said domain via a communication node in the outside of said domain according to a unicast routing procedure;
• and
• wherein, when a predetermined communication node in said domain receives said packet, said predetermined communication node transfers said packet to said mobile station according to a multicast routing procedure, and said packet includes a multicast address having a domain address for specifying said domain and a group address for identifying a group of said mobile station;
• said mobile station comprising:
• a multicast address registration part for registering said multicast address;
• a domain obtaining part for obtaining said domain address which specifies a domain to which a communication node for said mobile station belongs from said communication node for said mobile station;
• a domain address determination part for determining whether a domain address obtained by said domain obtaining part and a domain address included in a multicast address registered by said multicast address registration part are the same;
• a sending part for sending said multicast address to said communication node for said mobile station when it is determined that said domain address obtained by said domain obtaining part and said domain address included in a multicast address registered by said multicast address registration part are the same;
• and
• wherein said communication node for said mobile station transfers said packet to said mobile station by using said multicast address.