SIP Trunking

Feature rich, high quality IP-based telephony solutions that are future-proofed and save you money.

SIP, or Session Initiation Protocol is in essence signalling for IP telephony calls, and a SIP trunking enabled link is one that enables IP telephony calls to be carried between the user and the carrier such as WXC.

SIP Trunking links can also carry data, which allows you to converge your voice and data circuits onto one link. One of the biggest difference between SIP calls and legacy PSTN or ISDN calls is that SIP Trunk calls use IP telephony, which in turn uses packet switching to carry calls across a digital network, as opposed to circuit switching used in legacy networks. This enables more efficient use of the access link – for example, a single SIP Trunk could carry several hundred simultaneous calls, which would otherwise need several Primary Rate ISDN links, each only capable of carrying 30 calls.

The quality of the underlying network is key to the operation of IP telephony, and we should note here that WXC uses its own private IP network, guaranteeing both Class of Service and Quality of Service, unlike “The Internet” which uses best effort delivery which has given Internet Telephony its less than robust reputation.


Reduced Cost

With PSTN & ISDN networks, you pay for lines and channels whether they are used or not. You also have separate data lines. With SIP Trunks, you get voice and data on the same access circuit and sharing the same core network, affording you the highest efficiency from your link.

Future Proof

SIP enabled IP Telephony is a platform upon which applications can be built to enable effective use of time, location and communication, allowing you to work smarter from wherever you need to, which opens up a whole raft of business benefits and efficiencies for both employer and employee.

Unified Communications

By using software to integrate voice and data applications you are able to do things like use local address books to dial numbers or to identify incoming calls, you can have voicemail delivered to our email in-box, and you can enable your calendar to control your voicemail message and presence settings, you can transfer calls between office and mobile and this is just the beginning.


SIP now offers High Definition voice and video – to enhance the user experience. A voice call made over a SIP Trunk can be proactively measured for quality using established global standards. WxC constantly monitors and rates the calls flowing through its network in accordance with these standards.

Enhanced Features

WXC believe delivering dial-tone over SIP is the absolute bare minimum. Real value is gained through the additional capabilities that meet business challenges. We've built our business on cracking tough problems using SIP technology. With WXC you'll get outstanding levels of visibility and control, as well as access to our dedicated software development team.


Avoid costly network down-time by deploying an IP voice network which is easier and faster to troubleshoot than PSTN or ISDN solutions. IP networks permit the interrogation of call setup and quality with ease, resulting in far more detailed analysis. WxC runs a Network Operations Centre dedicated to the proactive management of its services.


Because SIP Trunks use virtual circuits, it is easy to add and remove capacity – catering for organisations with seasonal peaks. No longer do you need to dimension voice capacity to meet peak requirements - and then pay for that capacity all year round. With SIP you have a far higher degree of flexibility and control.