D channel packet communication system and a method of D channel

D-channel voice communications

Data access server for PBX

Data call routing on IP connections

Data communicating apparatus and data communicating method...

Data communication apparatus and data communication method

Data communication apparatus and data communication method

Data communication method

Data communication method

Data communication method and apparatus

Data communications system with splitterless operation

Data gateway and method for relaying data

Data manager for wireless communication devices and method...

Data network and PSTN telephony system

Data network computing device call processing

Data network for real time information

Data network interface and communication devices having a...

Data network security system and method

Data packet router

Data session setup system for wireless network