Call setup and media ports

To place calls to other systems through the firewall, you must configure your firewall to allow incoming and outgoing traffic to the system through the following:

UDP port 1719 Gatekeeper registration.
TCP port 1720 H.323 call negotiation.
UDP port 5060 SIP call negotiation.
TCP port 5060 SIP call negotiation if TCP signaling is enabled for SIP calls.
TCP port 5061 TLS signaling in SIP calls if TLS signaling is enabled.
NOTE: TLS is the only transport supported for encrypted calls.
Required TCP
and UDP ports
Range specified inPreferences > Network > Reserved Ports.