VoIP Specialists

We live and breathe VoIP all day every day, so if your challenge is getting VoIP to work in your home, office or on the road we can help.

IP Trunks

IP trunks offer a more flexible and lower cost alternative to ISDN for inbound and outbound voice calls. SIP trunking is a standards-based replacement for traditional ISDN. It connects your PBX to the PSTN via broadband, ethernet or private circuit into our national network.


Compared to ISDN our SIP trunking service is less costly per channel and more flexible in how and where geographic telephone numbers can be used. It’s also quicker to install and provision and, as standard, it delivers extremely robust business continuity.


The service can support connections ranging from two channels for small PBX-equipped businesses to an unlimited number of channels for large enterprises and contact centres. Scale up and down when you want SIP trunks –  ideal if you are moving, upsizing or downsizing and want to keep your existing numbers. Scale up lines during busy periods and back down again afterwards. You can add lines, take them away, split calls at any time. You are always in control.

Ready for Anything

Built-in Business Continuity; SIP trunks can handle emergencies easily. They are inherently disaster recovery / business continuity ready, letting you reroute calls to an alternative location quickly and easily.


ISDN lines in contract-Not a problem; Grapevine can connect existing PSTN/ISDN lines to our cloud PBX and these can be utilised for the remainder of the contract to limit early termination fee’s and migrate to VoIP trunks when your business is ready.
Our Case Studies

Find out about the work we have done for our clients.


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We specialise in solving communication challenges. Challenge us to get you connected.