
Explanation:

You can configure the TCP port that's used to listen for Session Initiation Protocol (SIP) requests on a Unified Messaging (UM) IP gateway. By default, when you create a UM IP gateway, the TCP SIP listening port number is set to 5060.
The Microsoft Exchange Unified Messaging service and the UM worker process use multiple Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) service ports to communicate with IP gateways.
The Microsoft Exchange Unified Messaging service and the UM worker process use
Session Initiation Protocol (SIP) over TCP.
By default, the Microsoft Exchange Unified Messaging service listens on both TCP port
5 060 in Unsecured mode and TCP port 5061 when mutual Transport Layer Security
(mutual TLS) is used.
Each UM worker process that's created listens on port 5065 and 5067 (unsecured) and
5 066 and 5068 (secured).
But when an IP gateway or IP PBX sends Realtime Transport Protocol (RTP) traffic to the
Speech Engine service worker process, the IP gateway or IP PBX will use a valid UDP port that ranges from 1024 through 65535.