Introducing a New XML-Based Protocol for Sip User-Agent Services Collaboration: Integration with IP-Phone and PC

Some IP-phones are offering only a simple user interface with plain DTMF digits and optional function buttons, but without any graphical display. This kind of limited user interface makes cumbersome the usage of advanced IP-telephony services in many scenarios. Enhancing IP-telephony services with collaborative devices can both resolve the capabilities limitations of IP-phones and also encourage user location mobility. The introduced solution consists of using a third party device, such as a PC on an IP network, to make a connection with the IP-phone where the connection is realised with a specific protocol based on the session initiation protocol (SIP); this protocol benefits from the subscribe/notify mechanism defined by the IETF. By exchanging notify requests and by using suitable information encoding, the two devices are able to collaborate and can evolve together to carry out advanced IP-telephony services. On the scope of this work, some collaborative services such as the caller-id service were analysed, developed and implemented