Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Akihito Tsuzuki

Hiroaki Miyata

Yasuo Kogure

Munetoshi Tsuge

In a network having an L2SW in which uplink VLAN is set, a transfer delay of a voice call packet is prevented. In a process of establishing a session between terminals (), a packet transfer device () stores information capable of specifying a sending terminal (-) and a receiving terminal (-) and a correspondence relation (user connection information) to a connection port into a table. A SIP message of a session control packet communicated between the terminals () is snooped, and a destination IP address, a transmission source IP address, a destination port number, a transmission source port number, a connection port etc. are stored into the table. In a case where an RTP packet as voice data is received after the session is established, the packet transfer device () performs a loopback transfer or transfers it to an uplink port in accordance with the table.

Packet transfer device and communication system

Disclosed here is a communication apparatus and method for inter-AS routing, which enables policy routing between a stub AS and an upstream AS. The policy routing includes control which is applicable only between adjacent autonomous systems (AS's). When a subject communication apparatus notifies its own AS number or advertises attribute information that includes its own AS number to a stub AS, the communication apparatus does not use its own AS number or uses the AS number of the upstream autonomous system (AS) instead of its own AS number. In addition, when relaying routing information received from one AS to another, the subject communication apparatus also relays attribute information without discarding the information, although the information is conventionally not relayed to itself.

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Yokohama, Japan

Akihito Tsuzuki