VOX NOVA Fixed Voice OFFICIAL (FVO) & Enterprise Voice (EV)

1. Purpose

The Authority Enterprise OFFICIAL voice system is ageing and requires modernisation. The future end state is a hybrid solution that fuses on-premises calling capability with the flexibility of a cloud-native call management service.

This procurement is for the design, build, migration, and operation of the end state architecture whilst ensuring the users maintain capability throughout the process.

This encompasses design and delivery of a cloud native call management core (Software as a Solution (SaaS) or UK zoned public cloud), migration of existing gateways and SIP native Private Automatic Branch Exchange (PABX), modernisation and Session Initiation Protocol (SIP) enablement or replacement of legacy, non SIP PABX, through life support for legacy PABX estate until migration, resilient public telephony breakout and partner connectivity, local survivability for specific sites, a field engineering competence to ensure compliance with Authority processes and service management.

The existing PABX estate is mostly analogue lines with a small amount of digital and Voice Over Internet Protocol (VoIP) ; it is not envisaged that this will change due to the cost and complexity of replacing the existing cabling.

2. Background

The Ministry of Defence’s (MOD’S) Integrated User Services (IUS) VOX NOVA (VN) Programme is responsible for the delivery of fixed voice telephony at OFFICIAL.

The current FVO service supports Defence outputs, including safety-related and operational use cases. User access is provided through a mixed estate of analogue lines, digital extensions and a smaller number of Voice over IP endpoints, with services terminating on site-based Private Automatic Branch Exchange (PABX) where required.

The existing estate includes a mixture of refreshed IP-native OpenScape PABX, HiPath 3x00 switches and legacy Integrated Services Digital Exchange (iSDX) and Meridian switches. Site-based PABX trunks and Voice Over Internet Protocol (VoIP) handsets currently terminate on a geo-resilient call management core, with connectivity using Session Initiation Protocol (SIP) and Internet Protocol (IP)-encapsulated H.248 for legacy PABX.

Permanent overseas locations use OpenScape PABX with local public telephony breakout where required to support local survivability.

The current FVO core is based on in-service Ribbon C20 soft-switch infrastructure hosted in contractor facilities. It provides Time Division Multiplexor (TDM) and SIP trunk functionality, analogue terminal adapter support, H.248 media gateway support, public telephony breakout and secure boundary protection/partner connectivity

3. Outcomes the Authority is seeking

The Authority is seeking a resilient, supportable and Value-for-Money (VfM) service that maintains continuity while progressively removing reliance on the existing core and obsolete PABX estate.

a. Maintain continuity of critical fixed-voice services throughout mobilisation, build and migration.

b. Deliver a modern call-management capability using a secure cloud-native or Software as a Solution (SaaS)-based model, with on-premises survivability where required.

c. Migrate existing gateways, SIP-capable PABX and endpoints using controlled pilots and migration waves.

d. Modernise, SIP-enable as a priority and replace legacy PABX sites, including Meridian, Realtis, HiPath and iSDX, and other agreed non-SIP sites under the future-service delivery scope. Facilitate the withdrawal from the incumbent Data Centres by enabling legacy PABX to communicate to a SIP-based cloud calling platform. Replacement completed subsequently.

e. Provide specialist support to the legacy PABX estate, including Meridian, Realtis, HiPath and iSDX systems, for as long as each platform remains in service and pending modernisation and migration.

f. Provide resilient public telephony, partner connectivity, numbering, dial-plan, emergency-calling and local-survivability services.

g. Establish service management, monitoring, field engineering, security assurance, testing, early-life support (ELS) and through-life operations.

h. Provide a transparent commercial model covering implementation, migration, recurring services, consumption, spares, field engineering, change and exit.

The above describes the Authority's current outcome hypothesis rather than a prescribed solution. Suppliers are invited to identify alternative delivery patterns that better meet the outcomes, reduce risk or improve value.

4. Proposed procurement approach

Using the Competitive Flexible Procedure under the UK Procurement Act 2023 (PA23), the Authority will engage directly with all participating suppliers via direct dialogue and negotiation to further develop and optimise their bids.

Lot A Vox Nova

Design, build, integrate, migrate, operate and support the future VN service, including core platform, gateways, SIP estate and modernisation/migration of agreed legacy PABX and other non-SIP sites.

Includes SIP enablement, replacement, modernisation, migration, acceptance and operational support of transitioned sites.

Market Consideration - Vox Nova is expected to require broad capability across cloud or SaaS voice platforms, systems integration, security, migration, service management, public telephony, gateways, networking and through-life service delivery.

Lot B Legacy PABX support.

Provide specialist through-life support for the in-scope legacy PABX estate, including Meridian, Realtis, HiPath and iSDX systems, while each system remains operational and awaiting migration under Lot A.

Excludes SIP enablement, modernisation, replacement, and migration. Sites leave Lot B baseline after formal migration and service acceptance into Lot A.

Market Consideration - Legacy PABX support is expected to require specialist engineering expertise, access to appropriate spares, and experience in maintaining ageing or obsolete PABX platforms. The MOD is committed to supporting the Government’s SME (Small and Medium sized Enterprises) policy and wants to encourage wider SME participation throughout the supply chain. The MOD’s goal is for at least 25% of the Authority’s total spend to be placed with Small SMEs, either directly or through the supply chain. Lot B may sit with niche or specialist organisations, including SMEs, that do not have the scale or breadth required to deliver Lot A. Separating Lot B is therefore intended to:

a. Make the requirement more accessible to specialist suppliers and SMEs.

b. Avoid requiring a specialist legacy-support provider to bid for a substantially larger future-service transformation contract.

c. Allow the Authority to test whether specialist legacy support can be secured more effectively and economically through a discrete lot.

5. Planning assumptions:

UK -150

Overseas - 30

~113 sites; ~180 nodes; . up to ~65,000 telephone endpoint is any physical or virtual device that originates or receives calls.

Anticipated contract term: 5 years. Suppliers should treat volumes and dates as planning assumptions only.

Classification: Official