IP address acquisition method of IP telephone server in IP client device and the IP client device

摘要

PROBLEM TO BE SOLVED: To provide an IP client device in which the IP address of an objective IP telephone server can be acquired every time when predetermined conditions are satisfied, and communication can be established even if the objective IP telephone server is switched.;SOLUTION: The IP client device comprises a communication terminal interface means 5, a VoIP control section 6 having a means 8 for acquiring the IP address of a relevant IP telephone server 4a (or 4b) from a DNS server 3 by transmitting an address request for asking the IP address of a relevant IP telephone server 4a (or 4b) to a DNS server 4 only when three conditions, i.e. the IP address effective time (TTL: TIME TO LIVE) has expired, no IP telephone transaction is operating, and new IP telephone control is not yet started, are satisfied, and an IP network interface means 7.;COPYRIGHT: (C)2006,JPO&NCIPI