Abstract: A soft switch 134 providing wireless PBX voice services to a local area network (WLAN) is used to extend PBX functionality to the cellular domain. A dual mode remote unit is capable of receiving signals both in the cellular system as well as the WLAN. The cellular system is comprised of a data-bearing path and a voice-bearing path. When the dual mode remote unit is within the WLAN, it communicates both voice over IP (VoIP) signaling as well as session initiation protocol (SIP) control signaling over the WLAN. When the remote unit is outside the WLAN, it communicates voice signaling over the voice-bearing path of the cellular network using a standard cellular voice channel. In parallel, it uses the data-bearing path of the cellular network to transmit SIP control signaling.

Abstract: A system and method of serving text-based data messages to a caller identification (caller ID) system in a telecommunications network environment may overwrite source-specific information in a selected data packet header field with text-based message data. A protocol translator may enable text data to be served to a caller ID system used in conjunction with a plain old telephone service (POTS) telephone as well as with a Session Initiation Protocol (SIP) device. Text messages addressed and routed to a caller ID enabled device may be displayed on the caller ID display.