SIP Trunks

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SIP Trunking is the fastest-growing telephony service and Crystaline are the expert SIP Trunk providers of one of the UK’s leading solutions.



Crystaline’s Session Initiation Protocol (SIP) Trunks provide a highly-flexible alternative to traditional landlines and are compatible with all the leading IP Private Branch Exchange (PBX) brands in the UK market, giving you peace of mind.


Compared to traditional landlines, Crystaline SIP Trunks are cheaper on a per-channel basis and more flexible in terms of what telephone numbers you can have and the locations in which you can have them. In addition, they are quicker to install and offer a robust business continuity service that ensures your business never loses any calls.


Our service can support connections ranging from two channels for businesses, with no limit on the number of channels that can be supported for large enterprises and contact centres.

How Does it Work?

Crystaline SIP Trunks connect your PBX to Crystaline’s network, enabling full PSTN breakout on the public telephone network. Connection from your site (or sites) to our network is via an IP connection (for example broadband or Ethernet) and is delivered as an end-to-end service with an availability guarantee, voice channel guarantees and voice Quality of Service.

The Benefits of SIP Trunking