Category: Blog


The Countdown to SIP: Are You Ready for the ISDN switch-off?

By : Elliot Dacosta / 17 August, 2017 /

The Countdown to SIP: Are You Ready for the ISDN switch-off? 

The trend to stop offering ISDN as an option started with US telecoms giant Verizon ceasing to offer ISDN services to new customers. Similarly, in Europe the upward trend was continued when in 2015 BT announced their plan to migrate all users to IP networks and completely switch off ISDN and PSTN services by 2025. 

Although BT did not specify the reasons behind cutting off ISDN, the announcement didn’t come as a surprise since ISDN had been facing a decline year on year. According to Ofcom’s Communications Market 2016 Report, there were 7.6 million business fixed lines and ISDN channels at the end of 2015, 2.0 million (21% fall) fewer than there had been at the end of 2010. 

Even though ISDN has been diminishing for a while, there are still 3 million ISDN channels in the UK. Whilst It might be true that BT does not have all of these channels on their network, yet a considerable number of customers are BT’s and they will be left with no choice but to migrate in the near future. That is why it’s important to future-proof your business and get familiar with SIP lines and VoIP to ensure you don’t get stuck with legacy technology. 

At Solar we only work with the UKs leading SIP providers – TalkTalk Business and Gamma, which we recommend to help you make the transition seamless and alleviate any concerns you might have about moving to SIP. 

TalkTalk Business offers reliable voice connectivity between your PBX and their network. The benefits include increased flexibility, control, resiliency and reduced costs. A key aspect of TalkTalk’s SIP is that they provide global SIP on one network, billed by one company. This is unique in the market and attractive for large multinational enterprises. 

The other vendor we work with is Gamma, which is the biggest SIP provider in the UK. Gamma’s SIP trunks connect your PBX to the PSTN via broadband, Ethernet or private circuit into their national network. Gamma’s SIP works seamlessly with all of the leading IP PBX brands in the UK market. 

It is not just the BT 2025 deadline that is motivating businesses to make the switch, it is also all the benefits that SIP provides over ISDN. 

Here are the top 4 benefits of SIP Trunks VS ISDN: 

  1. Number portability and flexibility
    There are no geographical location requirements for your phone numbers. SIP permits use of 'out-of-area' numbers to since your phone number is attached to an IP address instead of a physical telephone line. So, for instance a New York number may point to an office in London. Additionally, ISDN takes 6-8 weeks to implement, whereas SIP takes 24 hours to spin up and spin down. Furthermore, SIP Trunk Quality means that call quality is superior to that of ISDN.

  1. Cost-efficiency
    The bottom line is important for every business and with SIP the savings are substantial. With ISDN, your voice and data are on different lines, whereas by moving from ISDN to SIP you can reduce costs by running both services over a single line. Also, SIP trunks can greatly reduces call charges including any international calls. Not only that, you'll benefit fromd free calls between multiple sites and offices on the same network. 

  1. Scalability
    SIP is deployed across your business’s existing network which means you can add additional trunks in times of high demand and subtract them when demand is low giving you the flexibility to easily scale your telephony as your business needs change. 

  1. Disaster Recovery
    Incidents happen and at some point your service could be interrupted by a network failure, a hardware problem, natural disaster or just bad weather. Luckily,  one of the biggest benefits of SIP Trunks is the better reliability and much simpler disaster recovery when compared to legacy phone systems. If your business needs a zero downtime environment, SIP trunks allow automatic failover solutions to be implemented so that your numbers will divert to other locations without loss in service. 

Want to Learn More? 

ISDN is Dead, Long Live SIP



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