What are SIP trunks?
SIP trunks are telephone line trunks delivered over IP using the SIP protocol. Using this standard protocol,
telecom service (VoIP) providers connect one or more channels to the customer’s PBX. Phone numbers and DIDs are linked to the SIP
trunk. In many cases numbers can be ported to the SIP trunk.
Benefits of SIP trunking
But our farewell to the PSTN brings many benefits.
SIP trunks deliver:
Lower monthly Line & DID Rental – The monthly fee to have a number of lines installed at your office drops
significantly with SIP trunks. And DIDs cost a lot less.
Lower call charges – There are many SIP trunk providers and competition has
driven down call charges significantly. Some SIP trunks even come with unlimited calling.
Better customer service – Provide better
customer service by adding more geographical and international numbers. Quickly and easily add numbers to your SIP trunk and terminate
them on your InTouch Digital PBX – you can give customers more options to dial in at a significantly lower cost.
Customers can contact
you more easily and sales will increase
Move offices and keep the same number – SIP trunks are not bound to a location, so
it’s easy to move offices without having to change your stationary or inform your customers. There is no longer any need to pay to
forward phone calls to the new offices.
Flexibility – It is easy to add channels to your SIP trunk to cope with increased calls. A
simple phone call will allow you to add channels, and often this can be done immediately. Compare that to the delay in having additional
lines installed and then having to upgrade your old PBX to
handle more lines!
Correct number of channels – With SIP trunks, you
can easily choose the correct number of channels that you need. Using ISDN/T1, you often have to choose to add either 15 or 30 lines.
This usually means you end up with expensive extra capacity.
Selecting the right SIP trunk provider
The next step is to choose a SIP
trunk provider who will supply the necessary SIP trunks. A few factors come into play when making this decision:
Security – As
SIP trunks are exposed to the Internet, it is very important that the SIP trunk has a well secured network and an anti fraud system
in place. The anti fraud system must monitor the system and provide protection against call fraud.
Competitive Cost – Look for competitive
rates, but ensure that you are getting business quality SIP trunk service. For example, telecom providers will provide a cheaper quality
to Internet call shops. Be cost conscious, but expect to pay a bit more for business class service.
Number Porting – Can the provider
port your phone numbers? Ensure that you choose a provider who can port all the existing numbers – not all providers are able to do
this for all regions.
The trusted old Public Switched Telephone Network (PSTN), with its Analog, ISDN BRI, E1 or T1 lines, is to disappear. Telephony
is moving from PSTN to much more modern and flexible SIP trunks.
The big telecom providers are fast phasing out the old PSTN functionality,
and are moving customers to IP. And so a SIP trunk and a phone system upgrade in the near future is going to be inevitable.
will phase out ISDN in the U.S. by 2018. In the UK, ISDN lines are down to less than 3 million lines, from 4.7 million lines in 2007
and the trend is accelerating. By 2017 major telcos such as BT, KPN, France Télécom, Deutsche Telekom and Telecom Italia will no longer
offer ISDN lines
As a result Session Initiation Protocol (SIP) trunking has increased by 62 percent in 2015 from the prior year,
driven primarily by North America. This guide explains what SIP trunks are, their advantages and how you can make the move.
all the leading SIP Trunk providers, for more information and pricing on some of the VoIP SIP trunk providers see: