SIP is an acronym for Session Initiation Protocol. This might not mean much to you at the moment. however it is one of the most rapidly growing technologies in telephony replacing ISDN2 and ISDN30 technologies.


SIP is an acronym for Session Initiation Protocol. This might not mean much to you at the moment. however it is one of the most rapidly growing technologies in telephony replacing ISDN2 and ISDN30 technologies.

We are experts in SIP;and a leading UK SIP Trunk provider DMV: Guaranteed Business SIP Trunk & SIP Trunking services for Business SIP Phone Systems.

Key reasons to use DMV SIP Trunk services:

  • Save over £3,000.00 per year compared with ISDN30e Rental
  • Save over £1,500.00 on ISDN30e Installation.
  • Guaranteed call quality – via DMV Ethernet or DSL
  • Keep existing phone numbers, or new UK numbers
  • Best value calls – giving you even more cost savings
  • Ideal for all DR requirements

For further information about how DMV can get SIP trunking working for you please email: or call DMV now on 0121 366 8888. We provide UNLIMITED FREE SIP TRUNKS please contact us on this time limited offer.


SIP Trunking allows business customers to lower costs, increase resilience with a Disaster Recover strategy, improve flexibility and use multiple new and existing phone numbers anywhere in the UK.

DMV SIP Trunks are a genuine alternative to ISDN30e – with us providing a managed service covering the IP connectivity, SIP Trunks and number management – exactly the same as with ISDN30e. We take responsibility from day one for delivering a robust business class SIP Trunking solution.


  • Up to 50% cheaper than BT ISDN30e – Rental and Connection.
  • Ideal for use with DMV Ethernet Circuits.
  • Shared voice and data circuits will save even more money.
  • Keep your phone numbers when moving – to anywhere in the UK!
  • New phone numbers from any UK dialling code, or use numbers from multiple UK dialling codes – regardless of your location.
  • Porting of BT numbers as well as our own UK-wide number ranges.
  • Multi level Disaster Recovery and Resilience options.
  • Proven interoperability with 3CX, AudioCodes, AsteriskNow, Avaya, Beronet, Cisco, Draytek, Epygi, IP Cortex, Panasonic, Patton, Sark, snom, Switchvox, , Trixbox, Vega Stream and more.
  • Significant savings on  phone calls.


What is SIP?

A SIP Trunk is a facility provided by DMV that allows the placing of outbound calls and the receiving of inbound calls using an internet connection, rather than using an ISDN line. Calls to and from the PSTN are supported. They are fast becoming the standard technology that allows businesses to make and receive telephone calls without the need for an expensive ISDN circuit. The Quality of Service (QoS) has contributed to its increasingly widespread adoption. Session Initiation Protocol (SIP) is used to set-up and ‘tear-down’ telephone calls over IP networks, including the internet. It is this VoIP protocol that is most widely supported by modern devices, including IP-enabled PBXs

Why use it?

Having separate voice & data networks is a legacy from the technology used for voice and how data connectivity has grown to provide huge amounts of throughput for everyday communication. The switch from voice networks carrying data, to data carrying voice is a reconvergence of data after a 20 year split. As the withdrawal of ISDN has been announced, voice networks move more and more towards SIP. We began this move 5 years ago, as it appeared obvious that true convergence was always going to happen. voice & data convergence reduce cost and enables better functionality, bringing modern day flexibility to voice.

How can I guarantee call quality?

The key to call quality is that every single IP data packet, with it’s millisecond’s worth of conversation, arrives in the correct order and without any delay, so every packet arrives after the previous one, in a constant stream. To ensure this happens 100% of the time you need an Internet connection that has guarantees covering both up time/availability and quality, in terms of packet loss (packets never arrive), jitter (varying time delay between packets) and delay (how long each packet takes to be delivered). A key issue is that the Internet Service provider (providing your Internet connectivity) cannot guarantee that your traffic will be forwarded onto your ITSP (providing the SIP Trunks) without further delays, the data may be passing through multiple networks before it gets to your ITSP. Even if interconnects are in place, these may change and your service may suddenly deteriorate. Using an ITSP that is also an ISP (Internet Service Provider), such as DMV, means that the data packets are delivered directly to the voice network and assembled as a telephone call without any extra delay – this guarantees that you have a single provider who, with the right circuit, can guarantee call quality and ensure ISDN30e call quality.

Numbers – UK & International

DMV has millions of UK numbers covering the whole of Great Britain. All ready to instantly provision and commission onto your PBX. Need international numbers? They can also be ordered on our portal and delivered by SIP.

Number Provision & Number Porting

DMV have our own  numbers allocated on all UK dialing codes – allowing you to have the dialing code you require. Again, this gives us control over your numbers, rather than relying on a 3rd party as many smaller ITSPs have to do. In addition to this, any BT number, and numbers from many other providers can also be ported to our network – allowing you to retain your current phone number when moving premises. One of the great advantages of SIP Trunking is the ability to have numbers from any dialing code delivered to your office – regardless of it’s location.  You can therefore have a mixture of London and Glasgow numbers delivered to an office in Birmingham – as well as local numbers – ideal if you want to give a local presence to your business.

Moving location or just want to move to SIP? You can keep all your numbers which will be moved over to DMV. We realise your numbers are important to you, so a dedicated provisioning team look after the process.


Allowing all types of communication; voice, data & video to use the same network has been around for many years. The efficiencies can be great, but it must be integrated correctly. DMV have a strong background in converging your network.

Fraud & Threat Detection

Every time your PBX registers, we scan your system for threats. We are trying to find security threats before hackers do. Coupling threat and fraud detection provides an outstanding level of comfort.

Vital for any business with call traffic due to the risk of fraudulent activity within the industry which is not just limited to SIP. Fraud is not new to the telecoms industry but DMV`s approach to managing the risk of fraud is. Included in the price of a SIP Trunk are two of the best methods in operation in the market today. We haven’t eradicated fraud but we have provided piece of mind that should you be the target of fraud your DMV account will warn you and automatically be suspended.

Backup Options

SIP is ideal as a Disaster Recovery (DR) solution , with multiple levels of resilience. The first level of resilience is the ability for SIP calls to be routed to a different IP address, i.e. a back up Internet circuit, or a circuit at another location. The second level of resilience is to be able to divert calls to a back up ISDN30e or local telephone numbers – this can be done on a DDI to DDI basis. Most users will not even know there is a failure. As an alternative, or if you don’t have back up lines on site we can forward calls to multiple external numbers, again this can be done on a number by number basis, do individual DDIs can route to home or mobile numbers on a person by person basis. This is ideal if you are concerned about your main site being inaccessible or inoperative. Any number on the DMV network can be forwarded to any other location – as long as it is connected via a SIP Trunk or a normal telephone line. This DR flexibility is just not available with ISDN30e – please discuss with us your requirements and we will construct a DR plan that suits you.

Auto Failover & Disaster Recovery

If your PBX doesn’t respond or register regularly DMV will automatically route the call to an alternative number landline, mobile or PBX. If the customer has 100 DDI numbers DMV can route each individual number to a different number. Find out that your PBX is down before your customers do. Monitoring and recovering from a number of voice issues can easily be setup on the DMV portal.


The core network supports T.38 fax protocol to end user devices. If you need to use T.38 please let us know and we will enable the configuration for you at no extra charge. If your PBX does not support T.38 you may experience problems sending and receiving faxes over VoIP lines. DMV are able to offer a Fax2email service which will allow you to receive faxes direct to your email inbox.

Call Recording

All in and outbound calls are recorded, saving the expense of on-site call recording equipment. Once your lines have been added to the recording, you will be provided with portal account to access all recording and down load when and if required. Simple and easy to administer and use.


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