Moving from ISDN to SIP: the key steps you need to take

Making the move: 5 easy steps to SIP migration

Since the late 80’s ISDN has been the de-facto telephony solution of choice, however, with no significant development in over a decade, it’s time for ISDN to retire for good. SIP trunking is fast becoming the obvious replacement for traditional ISDN services. This has been driven by both the need for a more flexible approach to ‘voice’ and the requirements of Unified Communications.   

If your organisation is considering the move, here’s our quick guide onto how the process will work:

Step one: scoping the job

Work with your communications provider to find out what the move will look like for your business. This may be a wholesale switch in one move, a phased branch by branch transition, or even floor by floor. SIP can work alongside ISDN, so the switch needn’t be fraught with the panic of turning one system off and another on at the same time. Costing will also be included within this part of the process.

During this period there should be little or no disturbance to your business. And any tests or checks can be carried out in a controlled environment.

Step two: audit the current system

A big part of the process from the customer end will be auditing current infrastructure and network capacity. Essentially, the provider needs this information in order to understand the optimum service provision required to meet business demands.

This can include the available bandwidth on the existing data connectivity, to decide if additional or dedicated connections are required to carry voice traffic. As with any audit, it will be a case of check and check again to ensure everything is accounted for.

Step three: installing the new system

With the project scoped and budgeted, the next step will be to begin installation. As SIP trunking comes with less physical infrastructure than ISDN, you will notice a substantial change in what has to be stored and maintained on site. Also, because SIP can work alongside ISDN whilst the installation is taking place, there should not be any real disturbance to your business systems during this stage of the process.

Step four: testing and checking

Unlike ISDN, a modern SIP-based phone system can integrate with business applications including Skype for Business. It also comes with built-in resilience and business continuity features. Each of these will be tested thoroughly before anything goes live to ensure the new system is working as expected. The IT department may find itself a little busier than usual during this period. But workers, at large, shouldn’t notice a thing as your provider checks your new system.

Step five: go live

Time to turn the new system on. With all the checks done and continuity provisions in place, this stage should be less uncertain than it may first sound. Depending on your initial plan, the ‘go live’ could happen in one month, one day or one hour. The important thing is to note that if steps one to four have been completed correctly, step five should go smoothly.

Migrate to SIP

To learn more about SIP trunking and how you could save money by upgrading from your traditional ISDN system click here. Alternatively call us on 020 3668 0444 or email

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