ISIP Case Study: End of Life PBX with ISDN2


A Salisbury based fabric printing firm has a legacy Panasonic KXT 1232 PABX with a 4 port Basic Rate Interface (BRI) module providing 8 channels of ISDN2e. The system had no voicemail or boltons but they do receive orders frequently via Fax Machine. They have a main bearer number and 55 DDI numbers which all route to the Panasonic handsets via traditional CW1308 telephone cabling. They would like to move to a hosted environment but, having so many DDI users, the cost of doing this is too expensive so they are looking for an alternative path.

The 2025 Challenge

The printing firm have physical cabling restrictions because of their current telephony set up. They also prefer to pay for equipment and any work done as it gets done, so have no desire to sign up to annual deals or contracts for hardware. Going fully hosted in the first instance is too expensive considering their 55 DDIs that need to be converted to Hosted Seats and handsets as a one-off payment, so the full ‘all at once’ hosted solution is not suitable. Their infrastructure will need a complete overhaul and a move to new connectivity and IT hardware focus too. There is a lot to take on board and do.

The business is very aware of the 2025 PSTN Withdrawal and are based in a trial area that must be moved prior to 2022, so understand they need to act now. They are keen to make a move into hosted and UC services and to get a flavour for IP telephony without the immediate associated workload and costs. This is an all too common situation.

The Solution

It is possible to provide a solution to the firm’s PSTN End of Life predicament using the ISIP8 device. A fluent order and provisioning process is in place to get the 8 channels of ISDN replicated via a VoIP hosted environment using HV.Select SIP.

Their main bearer number, along with the 55 DDIs, can be ported onto the HV.Select platform and be set up as SIP-T users on the HV.Select portal. They can then be assigned to an HV.Select SIP trunk and then registered on to the ISIP8 device. The ISIP8 converts the SIP provision back into traditional ISDN2e and will connect the ISDN channels to the Panasonic KXT PBX in exactly the same way as before.

Step by step guide to getting more from the HV.Select SIP and ISIP Device

Step 1: Provide cost savings and take the first step towards IP

Using HV.Select as the SIP carrier, the sites can have their numbers ported into the HV.Select SIP platform and are set up as ‘SIP-T Users’ on the same company on HV.Select.

This allows the service to be provided over a SIP trunk whilst retaining the on-premise equipment and ‘pay per concurrent call model’ an ISDN offers, plus, with HV.Select SIP, the firm benefits from inclusive minutes. The ISDN to SIP Converter, ISIP8, is paid for on a return on investment the firm makes via saving on the pence per minute calls.

Step 2: Enhance the legacy PBX experience

The fax machine the firm uses for receiving orders can be disposed of and a ‘fax to email’ feature can be set up on the hosted platform. This has its obvious benefits to the printing firm. No more machine being the primary benefit and paper-free working being second, providing a more efficient way to store orders on their IT systems, easily accessible by the company’s accountant.

Additionally, the business can now make use of voicemail messaging for the main number and any of the 55 DDI users, which can also be sent to an email address and automatically deleted from the cloud using auto deletion options so they never miss a telephone order.

Step 3: Impress with Cloud features

Managers and directors or vital staff DDI numbers, if not all the 55 DDI users, can be upgraded to chargeable SIP user licenses, which include UC features such as UC Office desktop, tablet or mobile. This means that, as well as the calls continuing to be made and received on the legacy Panasonic desk phones, they can be handled or even handed off to a hosted application registered to the user number, very much the same as a hosted user. This can improve home working availability and general mobility around the office and wider country and pave the way with some conferencing and collaboration features that UC Office and the HV.Select room bridge provides.

In addition, the ‘Go Integrator’ license and application can be deployed for each of the users to gain click-to-dial features, DDI management, Outlook and CRM integration.

The client can enjoy PCI compliant call recording too and apply call analytics to gain call traffic reports. The world of hosted communications and UC is offered up to this legacy user whilst using HV.Select as the SIP carrier for this solution.

“Using the ISDN to SIP Converter opens doors for businesses who have been previously stuck on the PSTN with legacy equipment that’s not suitable for IP. It’s an easy, simple and cost effective method to move ISDN customers with IP incompatible telephone systems” – Claire Richards, Voice Networks Product Manager at DWS

If you’d like to find out more about our ISDN to SIP Converters, get in touch with our team today.

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