It has taken me a long time to get round to trying your tip, but I’m afraid it does not work. The H323Q931PortFlag parameter changes the port that the Tenor listens on; not the destination port that it connects to.
The release notes at http://www.quintum.com/support/code/DX/P101-14-08/RN_Patch_P101-14-08.txt confirm this:
“In the var_config.cfg file, you can now turn on a feature to block incoming
H323 calls. Set the following two lines:
H323Q931PortNum 1788 or some other number for listening port (other than 0)”
If I find another solution, I’ll post it here.