Connect SIP Trunking
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How do SIP trunks work?

SIP trunks / channels are digital VoIP “telephone lines” which can significantly reduce call charges for businesses of any size. SIP trunks / channels allow you to manage all the complex routing so that your phone system can be utilised to its maximum extent. Want the same inbound number in two different locations? Not a problem. SIP trunks plug in to new or existing phone systems (PBX’s), providing inbound and outbound calls over the internet – each trunk allows you a concurrent call.

Can I have an example?

Joe Bloggs Sports Outfitters LLC in the USA has been running many years, but they are opening their new site to cater to the UK market. They’ve got an existing call centre in the States, but they want a UK phone number, and don’t want to pay international call charges. By opting for SIP trunking, they get UK numbers, and their outbound call charges become local to the UK [with an outbound UK number], giving the perception that they are UK based. Plugging into an existing phone system (we have a list of supported phone systems) is no problem and solves the issue with no expensive upgrades.

Alternative to ISDN… wait, are they not turning that off?

Correct – the Integrated Digital Services Network (or ISDN, for short) is being turned off in the UK in two stages by Openreach. From 2020, it’ll no longer be possible to order new ISDN lines, and from 2025, they’ll be decommissioned. If you’re using ISDN lines to provide your telecoms, it’s a good time to start planning the change. SIP Trunks are not only cheaper but can scale up and down (perhaps for the Christmas rush!) in a matter of minutes.

Supported Phone System’s


  • 3CX
  • Asterix Free PBX
  • AudioCodecs Mediant Media Gateway
  • Avaya Communications Manager with ASBCE
  • Avaya Communications Server 1000 with ASBCE
  • Avaya IP Office 400 with ASBCE
  • Avaya IP Office V9 and Below
  • Avaya IP Office V10
  • Cisco Call Manager Express
  • Cisco CUCM 10.5 with CUBE
  • Ericsson LG iPECS UCP/eMG80
  • Microsoft S4B 2015 Lync 2013 with Sonus SBC
  • Mitel MiVoice Office 250 with MBG
  • Mitel 3300 with MBG
  • Mitel MiVoice Office 250
  • NEC SL1100/SV8100
  • Panasonic KS-NS/NSX Series
  • Samsung OfficeServ 7000 Series
  • Samsung Communication Manager (SCM)
  • Samsung Ubigate
  • ShoreTel Connect with Ingate SBC
  • Swyx SwyxWare IP PBX
  • Unify Open Scape Business

Benefits Of Verstech’s SIP Trunks / Channels

Unlimited* UK Landline
and Mobile Calls

With our Verstech’s SIP Trunks, you enjoy peace of mind with free 01, 02, 03 and most 07 calls included for £12.50** per SIP channel – making our SIP trunks easier and lighter to budget.

*subject to fair usage policy – 5000 01/02/03 & 2000 07 minutes per trunk per month – although the policy is applied to all the trunks, so if you’ve got 10 trunks, that’s 50000 & 20000 for the whole account.
** pricing subject to VAT at prevailing rate
***calls to numbers classed by OFCOM as FM1, FM3, FM4, FM5 and FM6 – usually UK O2, EE, Vodafone and Three numbers.

Extremely Scalable

Easily add or remove additional SIP Channels as and when you need them quickly.

Numbers for every UK situation

Add inbound and outbound DDI numbers for UK Geographic, National and 03 numbers.

Configurable Portal

Don’t open a support call for changes – manage your SIP trunks yourself. If you do need support our experienced team are just a phone call away.

Incredible uptime

With a 99.9% uptime rate – you can be sure that your SIP trunks / channels are online, when you’re online.

Market Leading Disaster Recovery

It’s the worst time for any business, but things do go wrong. The building burns down, or a natural disaster prevents your staff getting to the office. But the show must go on (can’t beat a Queen reference); and with our Market Leading Disaster Recovery, your numbers can be forwarded to another line in a matter of seconds. It’s better to know you’re prepared and ready for the worst, rather than wait until it happens.

Set your own Caller ID

Subject to some checks on the number [making sure you’re not ringing out as Buckingham Palace or anything crafty like that], we can allow you to set your own outbound Caller ID.

Portable Phone Numbers

If you’re bringing numbers to us, no problem – we can port 95% of UK Numbers to our service. If you’re leaving us, if we’ve provided new numbers, they are provided by BT/Openreach so you can be sure you can migrate the service if your requirements change.

30 day rolling contract

Our SIP trunks come with a rolling 30-day contract. That means, if ever you need to cancel, you only give us a months’ notice – there’s no minimum term. Additionality, for short term service enhancements (like we need an extra 40 lines for 1 day), there’s no contract at all.

Single Bill

Like all our CONNECT services, it’s on one bill with everything else – might as well try and keep the beancounters happy! It makes it very easy and transparent to see your exact spend.

Don’t want to manage your own PBX – why not consider our hosted PBX solution?

Cloud Voice and Porting ExeterCloud Voice ExeterProviding a new managed Voice Over IP System and Number Porting$View Case Study
Cloud Voice and Porting Exeter
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