This article originally appeared in the March issue of INTERNET TELEPHONY magazine

Although a SIP trunk can be viewed as a phone line delivered over an IP trunk connection to a network using Ethernet, broadband, copper, etc., voice is not the only thing the protocol can handle. It also manages data, video, chat, e-mail, presence, collaboration and conferencing.

SIP is a specific IETF-defined signaling protocol, and a SIP trunk is an integral part of the delivery of this protocol. However, the term SIP trunk means little to businesses looking to implement a communications solution. The matter is further complicated by individual service providers, who explain SIP to their customers by branding the term in order to reflect their own specific set of service offerings. The number of definitions contradicts and confuses the meaning.

The IP industry is still maturing. Industry shapers, like the SIP Forum (News - Alert), acknowledge the need for new definitions and increased understanding of SIP, and call for collaboration to create strategies for SIP’s growing ecosystem.

Forces for Change

VoIP – A factor driving the penetration of VoIP/SIP trunking continues to be the adoption rate of VoIP by residential users. Residential bundled packages of cable and calling services enable business owners to experience the cost savings and usage of VoIP.

Mobility – Fixed mobile convergence, SIP-enabled smartphones and unified communications are increasing the demand for SIP. SIP-enabled devices can reduce the cost of communications via cellular networks by using the Internet for transport.

Business Continuity – SIP networks can be designed with multiple telephony and application service providers to ensure there are no interruptions to business applications or services in case of a failure. The use of SIP in support of an application increases its survivability and availability.

SIP is transforming how businesses communicate and collaborate. There is much to learn as businesses transition to and expand their use of SIP. However, as the protocol evolves and is updated to support additional applications like FoIP and UC there will continue to be a blurring of the lines between the protocol and the applications it supports.

SIP is changing the way communications is defined. It is no longer simply a device-to-device concept. It is instead user to user, without application or geographical limitations.

SIP is therefore, a protocol supporting a user-to-user communications paradigm that utilizes any device, any application, anywhere at any time.