£400 per day
Outside Spy
Remote (United Kingdom)
Senior Telephony Engineer - 12 Months - Outside IR35 We are seeking a Senior Telephony Engineer to support a large-scale programme to retire Legacy PSTN/ISDN services and transition to modern VoIP and SIP-based telephony platforms. The role will provide technical leadership across discovery, architecture design, migration planning, and delivery oversight, ensuring business-critical voice services remain resilient throughout the transition. Key Responsibilities: Estate Discovery & Risk Baseline Conduct discovery of the existing PSTN/ISDN telephony estate including lines, circuits, PBXs, gateways, and dependent services. Identify operational and service continuity risks associated with Legacy telephony infrastructure. Establish a baseline view of the current telephony environment and supporting infrastructure. Future State Architecture Definition Design future-state telephony architecture leveraging SIP trunking and VoIP technologies. Define...