ISDN Replacement
for Legacy PBX


ISDN replacement means a change from traditional ISDN30 circuits to SIP Trunks.

T4COM ISDN to SIP Trunks
T4COM ISDN replacement cost saving over 3 years

T4Com’s special deal for ISDN30 replacement:


If you are a company with a legacy PBX running 1 or more ISDN30 circuits we can offer a very special 3 year pricing model that gives you not only the immediate saving from changing to VoIP but we will discount our prices by a further 5% each year (INCLUDING YEAR-1). 

That amounts to an additional 15% saving at 24 months onto of massive cost savings from digitising your telecoms with T4com, the result being that over the course of 3 years your company could be saving £10,000’s on telecom costs


ISDN30 Replacement example

The following is based on actual data (real company, actual invoices etc.)

The business centre example had an Avaya phone system with an expensive ISDN30e circuit and monthly telecoms costs (calls + ISDN) of approx £947 per month. As with many businesses of this scale they also had a private internet circuit supporting their data requirements. This internet circuit had plenty of space for some VoIP calls. The combination of T4com’s ISDN/VoIP converter and our competitive SIP trunking and calls packages enabled us to give an easy saving of £441 per month! In this instance the customer could save even more as their actual requirements were for 26 channels (ie SIP Trunks) and the ISDN is 30 channels: T4Com SIP trunks can be right-sized and increased at short notice. Try that with an ISDN30!


ISDN replacement, how it works:

T4Com ISDN converters enable a customer with a legacy PBX to take advantage of SIP trunking with the attendant benefits of lower network and call costs. The network connectivity can either be via T4 LLU broadband or EFM or using the customer’s own private wire Internet service: the latter presents a substantial cost saving opportunity as the voice bandwidth is effectively free!

The ISDN converter is a 1U rack-mount unit that connects to your legacy PBX on-site using the existing ISDN port. NO CHANGES TO YOUR PBX ARE REQUIRED. The converter is connected using IP to either your existing Internet service or a new T4 provided alternative. All Media Gateways are centrally monitored and managed by T4Com. Your telecoms is safe with us.

The deployment of our Media Gateway ensures there is no disruption to the configuration of the existing phone system.

Each ISDN converter talks to 2 discrete T4Com SIP platforms in our Data Centres. From IP provider through to the interconnection to the UK PSTN: these platforms are separate in every respect.

T4Com’s ISDN replacement using our own SIP trunks, lines and calls can save you up to 50% compared with existing Analogue or ISDN services.

Call us now: 01252 364 385

For some of the industry's most competitive pricing options