[Asterisk-Users] Dialing analog extensions from SIP?

[Robert La Ferla]

Is it possible to group all analog (regular phone) extensions so that 
you can dial it from a SIP extension?   i.e.  for use as an intercom

I tried this:

[default]
exten => #3001,1,Dial(Zap/1,25,t,r)
exten => #3001,2,Hangup

but I just get a "Call Failed" and busy signal.  I would think this is 
possible but I'm not sure how to configure it.  I do have analog->SIP 
working just not SIP->analog.