The contractor must deliver and maintain a fully operational SIP trunking service. The work includes a dedicated 90-day Phase-In period to accommodate Local Number Portability (LNP) processing. Full Operational Capability (FOC), including successful porting of all existing telephone numbers, must be achieved no later than November 30, 2026. The service must meet performance and availability thresholds, provide continuous 24/7 support with defined response times, and ensure zero disruption to calling during the transition from the incumbent provider.