Pinnacle Telecom (Wales) Ltd

SIP Trunks

Quality calls over your IP Network

The cost-effective and flexible alternative to ISDN, providing flexibility and business continuity

SIP trunking is rapidly replacing ISDN services and Pinnacle is one the UK’s leading SIP trunks providers.
Our SIP trunks connect your site directly into the Pinnacle network via an IP connection to carry and terminate your inbound and outbound voice calls across the public telephone network.

Pinnacle SIP Trunks provide a highly-flexible alternative to ISDN and are compatible with all the leading IP Phone System brands in the UK market, giving you peace of mind that
your Phone System hardware works with the network service.
Compared to ISDN, Pinnacle 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 small Phone Systems, with no limit on the number of channels that can be supported for large enterprises and contact centres.

Flexibility with phone numbers

SIP trunking enables you to move office and keep the same geographic number without any ongoing call-forwarding costs or those associated with producing new company stationery.

Save money

IP connectivity costs less than ISDN with lower call costs, free internal calls between extensions and offices and lower line rental costs for multi-sites. Also, no expensive call-forwarding costs are required should you relocate or need to divert calls in the event of a disaster.

Business continuity

If your office has to be temporarily relocated in an emergency, this can be achieved quickly and cost-effectively with SIP trunking to keep your business working.


SIP trunking provides a phone service that will cope with any situation and give you business-grade resilience for your telephony. Whether you need to keep your business running in a disaster or emergency or you need to load balance your calls between sites during peak hours, SIP trunking delivers.

Line rationalisation

For businesses with multiple sites, SIP trunking provides the opportunity for line rationalisation and reduces the number of Phone Systems you need to maintain – while retaining full control of the numbers associated with your business.

Cost Efficient

Pinnacle SIP Trunks are integration tested and approved to interoperate with Skype™ for Business, allowing you to directly connect to the platform to make external calls.

How does SIP work?

Pinnacle SIP Trunks connect your Phone Systems to Pinnacle’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.

Pinnacle SIP Trunks and your Phone System

Pinnacle SIP Trunks have been conformance tested with all of the UK’s IP PBX manufacturers.
Here are just some of the IP Phone Sysetms and SIP Gateway vendors we work with: