[Asterisk-Users] Busy message

[Aaron J. Angel]

Eric Wieling [eric at fnords.org] wrote:
> On Tue, 2004-06-22 at 18:43, Simon Brown wrote:
>> This should be listed as a bug - it is not logical to go to busy,
>> when in fact the extension is unavailable.
> 
> I think the whole idea of "busy" or "unavailable" is flawed.
> Asterisk sets ${CAUSECODE} with the cause of the call being
> cleared.  You can use this to determine what you want to do.
> For exmaple if the cause code indicates "unallocated" then
> you should give the caller some indication that they number
> they dialed is disconnected or no longer in service.
> 
> I think I posed an example of how I handle this.  Check the archives.

What would the contents of CAUSECODE be when set?  I can't find
documentation of this anywhere.