Session Initiation Protocol (SIP) is an open industry multi-media signalling standard.

SIP, will be used to connect IP devices all over the world.

Whilst most of the world is already connected to the internet, and has the ability to share data and video over the internet, most business telephone systems are not connected. Many companies have deployed Voice over IP (VOIP) services throughout their organisation's, allowing free telephone calls across fixed links (such as broadband and MPLS services) for home workers and multi site offices, however at present, when it comes time to call a supplier, they have to use traditional services such as PSTN, or ISDN lines.

This is changing, eventually, most business and residential customers will be using an IP infrastructure connected to the internet, for voice calls as well as data & video. SIP is widely recognised as the standard which will enable interoperability between telephone systems from different manufacturers across this IP backbone infrastructure.

Using the SIP protocol, eventually all communications will be sent over an IP backbone infrastructure which will connect to the internet, and all IP devices.What essentially BT are doing with 21CN, is replacing all of their legacy infrastructure, the Public Switched Telephone network (PSTN) to make way for an internet protocol (IP) network.

In many organisations at the moment, all devices on their site are linked via Category 5 or 6 cabling, telephone systems, data networks, video, photocopiers, printers, security camera's, the list goes on. In the near future SIP will mimick this model, on a worldwide basis, we will be able to securely communicate with the people and devices we choose.

At Netco, we only sell systems which have the ability to add SIP trunks and extensions today, not the promise of SIP tomorrow, we do not have to wait for 21CN to develop, we can provide SIP functionality now.