How to make the move from ISDN to SIP: Part 2

Posted by: Jo Love
Category: Blog, Business Phone System

3 Reasons for Changing from ISDN to SIP



SIP trunking is not only less costly per channel for line rental than ISDN, but can also deliver savings on call costs, with many providers offering inclusive minutes as part of the monthly fee. SIP trunking requires less physical infrastructure, with fewer lines needed than with ISDN, in turn reducing the maintenance costs on required PBXs.

This is all the more important for enterprise businesses, who are likely to have multiple offices and more lines.

The bigger the business, the bigger the saving.


The beauty of a modern communications solution is that the addition of new lines and new office locations becomes a simple, pain free process. Line capacity to meet demand can be managed effectively without fuss and in most cases, call routing can be controlled easily, without requiring support from a supplier.

Importantly for growing businesses, it means that setting up new offices and remote workers does not require entire teams to stop working for installation to take place. Implementation can be seamless and in most cases the impact on productivity is minimal, if at all.

Number flexibility with SIP trunking ensures that if you are changing office completely, you can keep your existing numbers, even if you are moving to a different geographic location.


When a traditional ISDN connection goes down, it can be for days rather than hours. Also, businesses are reliant on their provider for a resolution, or to implement expensive call forwarding options reactively until the problem is resolved.

A modern solution, like SIP trunking or a fully-hosted phone system, comes with in-built resilience features. These solutions ensure that if something goes awry, business continuity can be maintained, with instant failover of voice traffic on to a different line or call plans that can include immediate redirection of calls to different hunt groups, office locations or even mobiles.

Due to this, thousands of UK businesses have identified cloud-based telephony as the future-ready technology they need to enable growth and agility.


GHM Communications provide telecoms and technologies to businesses – to find out if SIP is right for your business please contact us for an informal chat at any time.

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