Routing is selecting an appropriate path for a call. When a routing application is started, it sends route registration requests, which contain a device ID, to Avaya Aura® Communication Manager. Routing requests instructs the Avaya Aura® Communication Manager to send all incoming calls to these device IDs (in the TSAPI Service). The TSAPI Service sends the call to the application for routing.Avaya Aura® Communication Manager does not route these calls, also referred to as adjunct routing.