A session initiation protocol (SIP) trunk service connects a business’s telephone system to the traditional public telephone network via a dedicated IP connection, such as ADSL or an Internet leased line, for making and receiving multiple concurrent telephone calls.
And with BT announcing a firm date to switch off all its PSTN and ISDN services, we think UK businesses should consider switching to a SIP service sooner rather than later.
BT Group CEO Gavin Patterson said: “We already serve many thousands of customers in businesses using IP. Our goal is that by 2025, all of our voice customers will be served using IP with a premises solution and will migrate off the traditional telephony platform.”
SIP provides your organisation with many benefits including added flexibility and improved business continuity. It also offers substantial cost savings over traditional telephony services.
SIP trunks are provided at lower rental charges than other standard analogue (PSTN) or digital (ISDN) telephone lines plus have the added benefit of greatly reduced call charges and free calls between company sites.
They can be provided very swiftly and existing geographic numbers can be retained. As SIP numbers are attached to IP addresses, they have no geographic restrictions and can be routed to any location where an IP connection is available.
This means that if a business needs to relocate, or for business continuity in the event of fire, flood, etc, the published number can be transferred seamlessly without loss of service.
The non geographic nature of SIP trunks also mean that their numbers can be used for marketing purposes to create a local or national presence. For example, a business could have an Exeter dialling code number even if it is based in Bristol.
When considering a SIP trunk installation, it is important to consider the technical and cost merits of the various IP connectivity options available as the service is only as good as the connection used to deliver it.
SIP is often offered over broadband links which by definition are not carrier class and it would be a brave business manager who committed all of his voice communications to such a technology.
The call quality, the number of simultaneous calls required and the expected resilience should all be considered before migrating to SIP.
Want to know more? View a recording of our SIP webinar, which gives you a straightforward explanation on this voice service.
If you want to discuss migrating your business from PSTN and ISDN to SIP, please do not hesitate to contact one of our advisors by calling 0800 054 6789 or by emailing us here.