SIP Trunks

‘A SIP trunk will allow your business to access national and international benefits from VOIP telephony.’

A SIP trunk is a vital element for realising the potential of VOIP for your business.

What is it?

The acronym, SIP, refers to the predominant technology standard for the VOIP industry. It stands for Session Initiation Protocol. It was created by the Internet Engineering Task Force and popularised in 2002 when integrated with MSN Messenger.

A SIP trunk is a replacement for telephone or ISDN lines you rent from your telephony provider. Like those lines, a SIP trunk allows you to make and receive calls but using VOIP telephony.  

SIP trunk - the difference

A major distinction from conventional telephone lines is that you do not need a corresponding SIP trunk for each extension or telephone line that your business needs. With one SIP trunk from v4b your business can make and receive unlimited calls – unlike many other VOIP providers. This distinction translates into significant cost savings as it eliminates the need to pay for multiple line rentals.

Delivering returns

You need your business’s broadband internet connection and additional VOIP technology to get going with SIP trunks.

There are many options which we will consider against your particular set up ranging from:

  • connecting your existing PBX with a VOIP gateway;
  • replacing your traditional PBX with a VOIP one, known as an IP PBX;
  • installing a VOIP-enabled phone; and
  • tailored solutions if you are in serviced offices.

Whatever the combination, it will allow your business to access national and international benefits from VOIP telephony which include:

  • savings on monthly telephone line rental;
  • competitive call rates from anywhere worldwide; and
  • access to feature-rich services.

V4B recommends a minimum of 60 kbps of broadband capacity for every simultaneous call.

VoIP telephone lines coupled with our IP PBX solution enables your business to have direct inbound dialling for every member of staff, separate voice mail and telephone numbers in several countries.  For more details or to acquire IP telephone lines contact us at

 or call

+44 (0)207 442 2229 ; +61 (0)280 147185

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