asterisk users - Jun 2006 - Asterisk Zap/QSig with ChanIsAvailable

Hey,

we're running an asterisk system connected to another telco system using 
qsig. I'm currently trying to
use ChanIsAvailable to get the current phone status out of the foreign 
system.

ChanIsAvailable always return "0" - UNKNOWN. The Qsig protocoll itself
supports the feature to
query the status of a given phone.

Is there any other way beside to use "ChanIsAvailable"?

Thanks in advance!

Greetings,
   Michael