MGCP & CUCM Ports

[adamgibs7]

Hello,

I have a client with restricted open network port , I want to configure the VG224 analog voice gateway so pls confirm my thoughts are correct enough or I require more ports.

Analog VG224 to CUCM -----mgcp packets 2427,2428

PSTN VG to CUCM -----mgcp packets 2427,2428

Now for the actual fax data what ports I require to reach to CUCM and  PSTN VG.

Thanks

[David Hailey · Accepted solution]

MGCP call agent/gateway command processing is via port 2427.  2428 is used for PRI backhaul.  The actual "call" data (whether voice or fax) is the RTP port range of UDP 16384-32768.  

Hailey

[adamgibs7]

Thanks Dawid

just wanted to be know more according to your reply if it is RTP then when fax protocol t38 play its role.

thanks

[David Hailey]

Someone may swoop in and correct me but IIRC:

T38 is not a call setup protocol.  It relies on the underlying protocol (e.g. MCCP in your case) for negotiation.

[adamgibs7]

Dears,

Faxes are not going outside to the PSTN, i can see the packets leaving the PSTN router but actual data is failing. I am using VG224 where i can see the ports registered and also the faxt38 is enable on the Gateway configuration.

Any hints pls

Thanks

[David Hailey]

There's a lot that could go wrong here especially if packets are making it out to the PSTN.  Do you have T.38 end-to-end from the VG224 as well as the PSTN gateway?  Also, you'll need to check for errors/slips/etc. on the line as fax is very sensitive to these types of issues.  When you connect to the PSTN, do you get any fax data on the other end?  Quite honestly, you may be better served with opening a TAC case on this one.

Hailey