Patent ID: 8537808

Claim:
An SIP telephone set which makes a call through a proxy server to establish a session for a voice path with a call receiving device conformed to SIP (Session Initiation Protocol), comprising: a processor; and a memory; wherein said processor executes a request issuing unit which requests said call receiving device to establish a session for a data path by the pressing a specific key pressing sequence defined in advance at the time of establishment of a session for said voice path; a session establishing unit which obtains an access authentication result by the pressing of said specific extension to establish a session for a data path with said call receiving device; and a file obtaining unit which obtains a file managed by the call receiving device from said call receiving device independently of said proxy server after a session for said data path is established, wherein a file acquisition interface is provided by newly defined description in a media type of SDP (Session Description Protocol) for obtaining said file, wherein said file obtaining unit decodes said newly defined description and automatically obtains said file indicated by said newly defined description from said call receiving device, wherein said session establishing unit, when establishing a session for said voice path and data path, responds to a request for confirmation that no voice path will be abandoned from said call receiving device and instructs said file obtaining unit to obtain a file through said established voice path and data path after said file is obtained, cuts off the session for said data path, wherein said session establishing unit, when establishing only said data session, responds to a request for confirmation that a voice path will be abandoned from said call receiving device and instructs said file obtaining unit to obtain a file through said established data path and after said file is obtained, cuts off the session for said data path.