voice troubleshooting case debrief-h245 address

topology :

FAX server----ip2ipGW----TGW---PSTN--FAX1

Symptom:

Fax from FAX1 to FAX server is ok. But from FAX server to FAX1 failed.

Problem:
the Cisco GW doesn't send any H245 address info in neither callproc nor Alerting . XCAPI can not establish media channels.


XCAPI IPIPGW VGW ISDN
----------------------------------------------------------------------------------
H225 setup(H245address) > H225 setup setup
H225calproc(NO H245address) <- H225 callproc callproc
H225alerting(NO H245address) <- H225alerting alerting
??? <- H225connect connect


Root Cause:
This is an integration issue between XCAPI and the IPIPGW.

Normally, as sender (XCAPI) sends h225 setup out, the received (IPIPGW)should return so called H245address (its IP and port for H.245 connection) field in either callproc or Alerting message, and then the sender establishes separate TCP connection to this address as for media channels.

By default, the Cisco GW simply doesn't send any H245address info in neither callproc nor Alerting . XCAPI can not establish media channels.

Workaround:
delete the H245 address when XCAPI send one H225 setup
Fix:
add the h245 address onto IP2IP gw.
Please refer to the commands below:

voice service voip
allow-connections h323 to h323
h323
emptycapability
h225 start-h245 on-connect
h225 h245-address on-connect
call start slow