The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 2011
Filed:
Apr. 12, 2007
Akihito Tsuzuki, Yokohama, JP;
Hiroaki Miyata, Yokohama, JP;
Yasuo Kogure, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
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.