[Asterisk-Users] One way h323 to Cisco 7905?

[bam]

I've acquired a Cisco 7905 with H323 s/w that I have connected to *. It can 
make calls happily enough to H323 & SIP extensions and out to the PSTN, 
however when ever I try to call it from any destination the call fails with

H323:0 Could not call 192.168.9.23
Hungup 'H323:0'
Everyone is busy at this time.

TCPDUMP shows a short but spirited exchange between the 7905 and *, but 
nothing on the console to give me a hint. Anyone got any ideas?