North Essex Partnership University NHS Foundation Trust

VOIP Service Delivery to North Essex NHS Trust

CAS was commissioned by the North Essex Partnership NHS Foundation Trust (NEPFT), to assist in the delivery of a new N3SP managed voice over internet protocol (VOIP) service, to replace its existing analogue BT FeatureNet, managed service.

CAS was approached by the Trust director who requested an urgent meeting with CAS following previous projects that CAS had successfully completed on time and within budget, where it became clear CAS had the necessary skills in-house to deliver on a number of high profile ICT projects.

NEPFT was advised by BT that the existing FeatureNet analogue voice product was to be phased out. This left the Trust with little option but to start the process of planning for the removal of its analogue FeatureNet voice service as soon as possible. This necessitated seeking professional external help from an independent telecommunication specialist. Into the breach stepped CAS.

On winning this business, CAS immediately assigned a project manager to work with the Trust and its chosen voice service provider, N3SP, to deliver what was then the newly launched NHS voice service solution, (Hosted Voice Service and Local Gateway Services).

N3SP is and remains the main IT network provider to the whole of the NHS. It offered a voice solution that would be carried as an IP signal over a single network.

The Trust decided to utilise different aspects of this voice service, using Hosted Voice Service, (HVS), for the Trust’s smaller locations; and Local Gateway Services, (LGS), which would inter-connect with Public Automated Branch eXchanges, (PABX), for the Trust’s larger sites.

Hosted Voice Service (HVS) allows flexibility with regards to the number of subscribing users, and can be easily scaled up or downsized according to business needs. While the service is hosted by a third party contractor, the business has managerial oversight through its own administrator account.

Local Gateway Services are installed, in the case of NEPFT, directly to the telephone systems using DPNSS connections, with a specific number of voice channels over the IT LAN connections to the N3SP network.

This combined split voice solution achieved cost savings through:

  • improved annual rental charges
  • reduced tariff call charges,
  • a network design that would allow for free site to site calls over a 4 digit dial plan
  • Free nationwide calls to other NHS sites on the N3SP voice network.

These savings gave a greater level of resilience to the organisation and allowed the Trust, when ready, to also purchase other services, such as video conferencing and unified communications.

CAS designed the transition plan such that the Trust could migrate to the new services at its own pace. The use of a single contractor, N3SP, to manage the service meant all Trust locations could enjoy a comprehensive managed voice service over one unified IP network.

CAS was also requested to plan for the migration of all existing telephone users to the new VOIP service whilst maintaining a continual uninterrupted service.

The works included:

  • Site audits of all existing NEPFT locations, (approx. 38 locations)
  • Site audits also included reviews of the Trust’s larger sites, where existing PABX (Private Automated Branch Exchange) telephone systems existed.
  • Working with the Trust to deliver the N3SP – Hosted Voice Service (HVS).
  • Provision of telephone system specification of requirements, (SoR), to tender for the procurement of additional PABX equipment.
  • Working with the Trust to deliver, install and commission newly procured PABX telephone systems.
  • Working with the Trust to deliver the N3SP – Local Gateway Service, (LGS).
  • Planning the required interconnection to maintain the existing FeatureNet services whilst commencing migration to the new N3SP – HVS/LGS services.
  • Project planning the migration from the existing analogue FeatureNet service to the new N3SP managed VOIP services.
  • Maintaining/providing a high level of project support documentation, (site audit reports, project plans, network drawings, meeting agenda, minutes, engineering schedules etc.), during the life-cycle of the project deployment and roll out.

In addition to this voice project, CAS has supported NEPFT through several other projects


  • ICT refresh for the whole NEPFT estate.
  • Delivery of a number of new build programmes, 2 of which are used by the Trust, as major equipment / service centres.
  • Estate rationalisation – Downsizing/decommission ICT requirements within the estate.
  • Renovation of buildings, where careful ICT planning is required as the building remained live during the works, as continual service was paramount.