| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To save man-hours required for telephone contact by realizing detection of receivable/unreceivable state of a destination, utilizing a call control procedure by SIP, or notification of recovery to receivable state. <P>SOLUTION: Communication devices (100a/100b) mutually notify reception enabled/reception disabled state, using an SIP message (F4, F5) and transmit an reception disabled message in case of reception disabled state. The received side (F5) of the reception disabled message requests reset notice to reception enabled state, using a reception reset notice request message (F12). The communication device (100b) reset to reception enabled state transmits a reception reset notice message (F14) and notifies reset to reception enabled state, before executing the intended communication. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
