SIP Trunks

Modern Voice over IP Phone Lines

Moving voice calls from ISDN to SIP Services is a tried and tested way of saving money on both trunk rentals and telephone call charges and with the BT PSTN Network Switch-Off locked in for 2025 and End of Sale in 2023 it has never been more important to start moving to a SIP-based solution today.

GreenCity Solutions partner closely with Gamma Telecom for our SIP Trunk Solutions. Gamma Telecom are one of the largest network operators in the UK, with a reputation built on technical expertise and voice service delivery, they have an in-depth experience of VoIP implementations, working with organisations of all sizes.

SIP Trunks

Simple Per Channel Pricing

FREE Local Calls*

FREE Mobile Calls*

Reduced ‘Line’ Rental

Faster Change Requests

FREE Site-to-Site Calls**

Widespread IP PBX compatibility

Resiliency / Failover Options available

Set Fraud Management Spend Limits

*2000 Local Minutes per Channel and 2000 Mobile Minutes per Channel (3 Year Term). 

**Applicable where 2 or more Sites are using SIP Trunks as primary Trunk from the same supplier. 

SIP Trunk Call Manager

SIP Trunk Call Manager offers a powerful business continuity solution, giving you the ability to consolidate all your numbers onto a single platform and never miss a call.

Cloud-based call control allows you to automatically direct calls to a destination you define such as a colleague, mobile, hunt group or call queue. Combined with all the features and benefits of Gamma SIP Trunks, including our call bundles and the only fraud management tool that protects you and your customers by enabling them to set spend limits, SIP Trunk Call Manager is a hugely powerful business tool.

SIP Trunk call manager comes with a portfolio of business features such as Call Queuing and Voicemail to Email which, when combined with the ability for the user to fully control the service via a mobile app, provides a powerful business solution.

To find out more about our SIP Solutions call us on 01733830555 or use our contact form below. We will be happy to help and answer any questions you may have.

Frequently Asked Questions.

Can I keep my existing Phone Number?

YES! We can port your existing landline numbers (01, 02) from your current service to a SIP solution so you can continue to receive calls on those numbers.

With SIP Trunk Call Manager we also have support for Non-Geographic Numbers (NGN) such as 03, 08, etc.

When is the BT PSTN Switch-Off?

BT will shutdown the PSTN (Public Switch Telephone Network) in 2025 but will stop selling any services related in 2023. However trials in certain locations are happening as early as December 2020.

What happens if I don't move to SIP before the PSTN Switch-Off?

Any legacy PSTN services (such as ISDN) still live after the switch-off will be ceased. It is imperative to move to alternative services before this happens in order to avoid loss of service.

What if I need to keep my existing ISDN Phone System?

Check out our ISDN to SIP Converters which enable the ability to use SIP on Legacy Phone Systems that it isn’t currently possible to replace.