Ephemeral & MGCP 2727 Firewall Ports

[Flo.Matalis]

Hi Experts,

Just want to confirm below queries:

1. Ephemeral Ports

> For TFTP, from the Cisco's official firewall guide (https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/port/10_0_1/CUCM_BK_T537717B_00_tcp-port-usage-guide-100.pdf), Ephemeral ports (32768 to 61000) are indicated. May I know what's the purpose of this and if 69 and 6969 are sufficient ports?

2. Port 2727

> From Cisco's official guide, I cannot see this port anywhere. However, I read a couple of forums (ex. https://community.cisco.com/t5/collaboration-voice-and-video/mgcp-and-its-working-with-trace-example/ta-p/3155820, https://community.cisco.com/t5/collaboration-voice-and-video/mgcp-gateway-integration-with-cucm-and-pstn-service-provider/ta-p/3116588) that this is used to send messages from the gateways to the call agent. Is this really needed or Cisco needs to update their guide? Thanks.

Regards,

Flo

[Vaijanath Sonvane]

Hi,

TFTP uses UDP port 69 to establish network connections. However, the data transfer ports (i.e. Ephemeral Ports) are selected dynamically by the sender and receiver when the connection is initialized.

As per RFC 2705, Port 2727 is used to send commands from MGCP Gateway to Call Control Agent and Port 2427 is used to send commands from Call Control Agent to MGCP Gateway.

In Cisco UC environment, Port 2427 used for bidirectional communication between CUCM and MGCP Gateway. Port 2727 is not used.