Hello David,
thank you for the help. I already had a similiar config on the
cisco. Debugging SIP calls revealed that the cisco starts dialing
but imediatly terminates the calls and sends an "Internal Server
Error" SIP Message.
We now use an open H323GK and the SIP<>H323 converter as intermediate
and this solved the problem. We have a pretty good voice quality now.
best regards,
Arnd