The SIP Series (III): How do I replace ISDN?

How do you replace ISDN?

ISDN is fast becoming a technology of the past with the service set to be phased out by 2025 and replaced by SIP, an IP based service delivered over broadband and/or leased live circuits.

Here are some considerations that organisations need to think about when planning a move away from ISDN to SIP.

This is a great time to define your business needs and document your existing communications connectivity, for example, how many phone lines and numbers you have and where they lead to or terminate. Consider too what currently happens to calls if your lines are busy – are they queued or handled by voicemail?

Because SIP trunks are more flexible and versatile than ISDN this is also the time to map out how you could use and benefit from the new features that will be available once you have made the switch.This would include for example updating your disaster recovery and business continuity plans as SIP trunks can have user configured fail over to secondary circuits for resilience and/or call redirection to alternative locations. At the same time you can assess your remote and homeworking plans so that employees working outside of the main head office have access to free ‘on-net’ calls due to the fact they are on the same dialing plan.

SIP is perfect for seasonal business or planned changes in call activity volumes such as a sales and marketing campaign so you can factor these requirements in with your supplier – and remember, unlike ISDN with SIP you only pay for the services you use and not for spare trunks to sit idle when they are not required.

Many PBX phone systems designed after 2007 are compatible with SIP but today many users are ditching legacy, hardware based telephony solutions for cloud or hosted telephony and now is a great time to examine the deployment benefits of these new solutions. Again, with cloud telephony you only pay for what you use which is perfect for fast growing organisations and those with seasonal requirements.

When it comes to choosing a SIP provider then experience counts. A market leading supplier may not always have the cheapest headline pricing but instead have all the inter-operability issues resolved as well as the skills and support levels to ensure you always have the services you need up and running.

In the days of the URL, telephone numbers may seem quaint to many people but you won’t find a business card without one. So, the ability for a SIP provider to ‘port’ your existing numbers over to your SIP trunks is vital for customers confidence and business continuity.

The ability for SIP trunks and ISDN to run simultaneously and in parallel means that organisations have the ability to test out the new SIP service before contact your ISDN supplier to cancel their legacy service.

Finally, give thought to security and ensure you are not susceptible to potential DoS attacks on an unsecured phone system. A good SIP trunk supplier will be well versed in security mitigation and how you can prevent toll fraud.

 

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