What is SIP trunking?

SIP stands for Session Initiation Protocol (SIP) and is the way in which internet service providers allow the delivering of telephone services and unified communications across the internet. Customers have to be equipped with SIP private branch exchange and unified communication facilities in order to use the service. The software that operates unified communications then provide voice, known as Voice Over Internet Protocol (VoIP), video and other streaming media. For example desktop sharing or web conferencing are other benefits as is a shared internet whiteboard.

Such services can be used in both private and public domains. In a privste domain you are able to use the above services in a defined private network area. In a public domain the public switched telephone network (PSTN) or Public Land Mobile Network (PLMN) allows transmission of services.

In order to interconnect between a private and public domain a SIP trunk is required to allow compatibility across the two domains.

Internet Protocol (IP) allows the connection of the two domains involves setting specific rules that falls under the description of SIP trunking.

Your internet service provider is responsible for ensuring compliance with law regarding sharing data across the public domain. This involves tracking traffic, the identification of users and the use of the lawful interception procedures. Private domains are not subject to the same rules of law.

In both the public and private domains there are different elements that perform the required features of that are necessary in that domain. The result is divided in two, which are, access control and network-border elements. These separate the public and private domains and then implement all the internet service providers security policies.

The private domain has three levels. These are the corporate border zone which separated the public and private domains and implement the necessary organisational security policies. Central corporate switching node and IP-PBX’s.

The use of SIP trunking is widespread across the UK and used by many organisations in order to deliver their internal and external telephony requirements. These systems provide all the necessary functionality to allow organisations to operate their businesses successfully. A key advantage of such a system using SIP trunking is the seamless transition between internal and external data sharing arrangements whether that be voice or something more complex. SIP trunking is key to making such a system work effectively, ensuring that it plays its part in the business success.