ISIP Case Study: Hotel Chain with ISDN2 & PABX


A small London based boutique hotel chain has 4 sites, each has a standalone PABX with Basic Rate Interface (BRI) modules providing 4 channels of ISDN2e on each site. Each hotel has 2 ISDN2e Network Termination (NTEs) providing calls via a main number with 10 DDI numbers, used by the hotel managers and key staff, and a basic telephone in each room. The hotel chain needs a 2025 End of Life solution without having to replace the hotel’s key system and cabling infrastructure but would welcome upgrades and enhancements.

The Solution

Without the need for any work on the existing PABX key system, the PSTN ISDN2e can be replicated by installing 4 x ISIP8 ISDN to SIP Converter devices. These devices are licenced for 4 channels of ISDN2 for each site. The main hotel booking and DDI numbers 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 an HV.Select SIP trunk and registered onto the ISIP8 Device. The ISIP8 converts the SIP provision back into traditional ISDN2 and will connect the ISDN2 ports from the ISIP8 to the PABX key system in the same way as the PSTN BT NTE did.

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

Step 1: Porting and numbering

Using HV.Select as the SIP carrier, each of the sites 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 to an IP endpoint, such as an IP-PBX conversion device like the ISDN to SIP Converter ‘ISIP8’. Unlike other SIP providers, HV.Select SIP is available with so many extra features that can be taken advantage of.

Step 2: Configuration of the ISIP

The ISIP device can be configure within 1 page on the ISIP device management portal, with no need to change any on-premise PABX configuration, simply move the wires from the ISDN to the ISIP.

Having gone through the order journey for the ISIP8 devices, number porting, trunk configuration and device deployment, the ISDN2e replication is complete and can be left as is with no further thought or management.

Step 3: Impress with Cloud features

The immediate effect of using HV.Select SIP to connect the ISIP8 devices within a hosted enterprise is the Cloud imitation of telecom branch networking for this multisite hotel chain. This is the ability to call, transfer and distribute traffic between physical sites as if it were an internal call or in the same location.

Using this “by-proxy” environment, many of the HV.Select call management features could be used to handle and distribute calls across the multiple sites using a single number mode of entry, such as a hunt group, call centre or auto attendant. Since the members of these features would be a SIP-T user (DDI) number into a respective PABX via the ISIP8 device, an handled call will be presented to any respective site PABX. Those calls can then be manually distributed, if needs be, across the other 3 sites as if they were 1.

Step 4: Step into Hosted Unified Collaboration technology

‘SIP (DDI) users’ on the HV.Select platform can be uplifted to introduce UC features to the number, such as softphone; UC Office Desktop, Tablet and Mobile softphone applications along with Go Integrator for click-to-dial features and CRM integration. In this case, managers and office staff could use the UC Office mobile app to link up to their direct dial number so they can be reached when away from the desk, whilst travelling between sites and when locally mobile around the hotel floors within their allocated hotel. At the desk, Go Integrator can be utilised to assist in web browser click-to-dial functionality and CRM integration, all in unison with their legacy PABX handset and DDI.

N.B. There are limits to what can be achieved with the UC deployment across HV.Select SIP. This is generally dictated by the concurrent calls allowed per trunk at a site level. What this means is there will be a time where, if the UC Features are deployed and simultaneously used by more users than SIP channels available on each site, an all lines/channels busy could be experienced, much the same with a non-scalable PABX line to user ratio calculation.

Therefore, we say that the ISIP8 option can be used as the perfect solution to the 2025 switch off to all legacy ISDN PABX systems or in addition a service enhancing hosted platform. ISIP8 can be the very first step into the world of UC and ultimately a fully hosted or SIP/Hosted HV.Select solution.

Step 5: Explore the hybrid possibilities

With HV.Select SIP the hotel chain has the option to expand their telephone system with Hosted Seat Technology, again without having any work carried out on the legacy kit and wiring. Because HV.Select is a hosted seat and SIP hybrid platform, both fully hosted users and SIP Users with DDIs can exist in the same space and seamlessly interoperate.

It doesn’t matter at this stage what the chain have chosen as their solution. With HV.Select, they can accommodate the future of their business as well as ensure the immediate PSTN 2025 End of Life ISDN replacement is carried out, without any changes made to the existing equipment or on-premise call handling situation.

“We’ve worked with so many partners who struggle with their customers who simply cannot move to IP with their legacy PBXs and the ISIP device has allowed them to move to IP without the costs, then when the customer starts using the HV.Select features they are just blown away. It’s fantastic!” – John Walford, IP Specialist 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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