Onecom Blog Archive

ISDN to SIP – what does it mean?

Traditionally, Integrated service digital network (ISDN) technology allowed inbound and outbound voice calls through a ‘digital’ line – through the internet.

But SIP trunking is now replacing ISDN services, which means ISDN will slowly be phased out over the next 5 years. 

Why? Because it’s better technology. Think 5G replacing 4G, which replaced 3G in turn. Gradually, they are then phased out as new technology comes along.

Not only is it better technology, it’s also cheaper, more flexible and can help business future-proof their telecommunications systems.

What is ISDN?

ISDN stands for integrated service digital network. It originally appeared back in the 80’s but is still widely used in businesses. It became popular due to the fact that it allowed the opportunity to transmit both voice and data over the same line.

ISDN is a digital line that runs through copper wiring. It was a lot faster than traditional analogue lines and could be used for data as well as carrying voice calls. The main issue with ISDN is that it relies on physical infrastructure, the copper lines, which can be costly to maintain. It also requires an additional private telephone network that is used within the company (also known as a private branch exchange or PBX).

In a nutshell, ISDN takes up space, is costly to maintain and cannot easily be fixed when things break.

Replacing ISDN with SIP trunking

Session Internet Protocol (SIP) trunking is the next-in-line future-ready solution to replace ISDN. It’s still a digital connection, ensuring calls are transmitted via the internet. However, it connects the PBX to the network via broadband, Ethernet or a private circuit.

It enables you to make calls via the internet.

(NB: SIP is also known as VoIP, which struggled to take off due to early signal issues and problems. Therefore, SIP came along as technology advanced, enabling more reliable and scalable communication options for businesses.)

The trunking part? Well, that is a tech-jargon for a system which provides network access to many people by sharing a set of lines. Think of a tree trunk with many branches running off it or a network with a central hub. A ‘trunk’ is one communications channel between one point and another, typically one being the central hub.

SIP enables businesses to mange their communications more easily and have a more reliable solution that is flexible to their business needs.

Why does my business need SIP?

The main reason you should switch to SIP, is because ISDN is on its way out. BT completely plan to phase out ISDN by 2025, with Internet Protocol (IP) calling seen as a much-preferred alternative. We highly, recommend getting yourselves into the modern world and upgrading your phone lines. But don’t just take our word for it. Here’s more reasons why you should be looking at moving from ISDN to SIP.

How to prepare for the ISDN switch off?

 Whilst the official phase out isn’t until 2025, if your organisation resides within a stop sell area, this deadline could be sooner than you realise. If your business uses ISDN, you should start to think about moving to an IP service in preparation for the switch-off. In our OneTALKS webinar: 'Preparing for the ISDN/PSTN Switch Off - Your Questions Answered', we tackle the frequently asked questions we receive around the ISDN/PSTN switch-off, how to prepare and minimise the impact of this change, plus practical guidance on alternative telephony solutions to suit every budget.

You’ll save money

One of the major benefits of upgrading to SIP is that you can see unprecedented savings on your call costs. SIP means running your calls via the internet, which takes out the need for physical infrastructure and therefore, maintenance.

It is suggested that business can save up to 50% on their business calls on average.

What’s more, as your line is run through the internet, providers often give you inclusive minutes included within your monthly charge. You can make even more savings, the larger your business too.

You get flexibility

With SIP adding new lines is really simple – in fact, it can be done in less than a minute. Calls via the internet can help you to meet business demand and control where your calls go easily.

Setting up new offices or working remotely is a lot easier as there’s no need for installing new lines. It also enables a business to keep their existing numbers, even when they move locations.

SIP trunking is scalable, which means it can be grown with your business really easily.

You get more reliability

When traditional ISDN connections go down, it can be timely and difficult to fix. Your business can be out of action for hours, if not days. Business continuity is reliant upon maintain connections.

With SIP trunking you get a new level of resilience. Your calls can be diverted to a different line or redirected to another office. It also enables calls to be redirected to mobiles too, which can be great for remote workers or employees out for meetings.

Stepping towards SIP

Switching lines can be met with resistance. Particularly, because traditionally switching can cause disruptions within a business.

However, your switch to SIP can be flexible. You can switch in one move or phase the transition by each site, office or even floor. One of the best benefits is that SIP can actually work alongside ISDN so there’s no need to worry about down time.

In fact, there’s little disturbance to your business activities, if any. Testing and checks can be carried out in a controlled environment too.

With the ISDN switch off there is no good reason to continue using old phone lines. Especially, when you can save money, get more reliability and have calls that can meet your business demand.

For more information about making the transition from ISDN to SIP trunking, contact our team at Onecom today on 03333 44 55 01  today or get in touch.