Communications equipment giant Siemens has today unveiled a new guide to session initiation protocol (SIP), a hot new technology that can enable users to be contacted whether at home, in the office, or on the move. The technology works across most media channels, including PCs, phones, digital cameras, TVs or handheld devices.
Gary O’Callaghan, enterprise business manager of Siemens Communications, explains: “An example of SIP in practice is if you’re on a video conference at your desk and have to leave early, you can transfer the video conference to your wireless PDA to continue participating while in transit. SIP is still evolving and is being extended as technology matures and SIP products are still being socialised within the marketplace. SIP was closely modelled after HTTP and has become a strong, catalytic force shaping today’s telecom industry.”
The Siemens guide explains the concept of SIP by saying, “Think how many different ways you might try to track down a co-worker for an urgent meeting and how much effort is expended in the process. There are also many different devices we use daily to stay connected, PC, mobile phone, home phone, PDA, internet connection and so on. SIP is the protocol that facilitates convergence at the application level. It treats all media types in the same way and is supported on both wireline and wireless networks.”
SIP is a signalling protocol used for establishing sessions in an internet protocol (IP) network. A session could be a simple two-way telephone call or it could be a collaborative multi-media conference session. The ability to establish these sessions means that a host of innovative services become possible, such as voice-enriched e-commerce, webpage click-to-dial, instant messaging with buddy lists and IP centrex services.
The guide continues: “SIP can establish multimedia sessions or internet telephony calls and modify or terminate them. Most of SIP is about the initiation part, since this is really the most difficult aspect. ‘Initiating a session’ requires determining where the user to be contacted is actually residing at a particular moment. A user might have a PC at work, a PC at home, and an IP desk phone in the lab. A call for that user might need to ring all phones at once. Furthermore, the user might be mobile one day at work and the next day visiting a university. This dynamic location information needs to be taken into account in order to find the user.”
O’Callaghan concludes: “With communications becoming more ubiquitous this technology will become more important. With so many mobile devices and technologies, the line is blurring between home and work.”
By John Kennedy