DA from NHS Link: IT Solutions 2 FW for Gamma SIP Trunk Service for Corporate Telephony 2026-2029

Stockton and Darlington councils currently have a contract with Cisilion to provide a resilient SIP service to Xentrall Landing zone in Azure cloud of use by both. This SIP service carries all incoming and outgoing external calls for the councils and terminates on resilient Ribbon Session Border Controllers that route calls to Teams Voice in Azure or the on-premises Netcall CRM's used by both council's Customer services departments. These Ribbons servers are provided and supported by Cisilion in a separate contract. This contract also includes the provision of the current DDI extension number ranges e.g. 01642 52xxxx for Stockton. This DDI number provision also includes the Stockton "Gold Number" ranges which the council have had since the 80's. Cisilion were essential with the migration to Gamma SIP as part of the previous contract and we have been happy with that support and the help they have provided since then.