[Asterisk-Users] Please help, Zap channel hangup TE405P

[justiceguy at pobox.com]

Asterisk experts,
I have been pulling my hair out troubleshooting what appears to be 
a Zap channel disconnect on the TDM side.  I am trying to have an 
inbound call on a T1 zap channel on the TE405P from our Harris 
switch automatically dial a SIP channel.  Any help appreciated 
very appreciated.

When the call in extensions.conf executes the demo-congrats:
exten => 2145551234,1,playback(demo-congrats)

I hear the demo - success.

When the call in extensions.conf tries to automatically dial a SIP 
channel:
exten => 2145551234,1,Dial(SIP/100)

Asterisk sends an IVITE to the phone followed by an immediate 
CANCEL.  Asterisk console debug looks like the Zap Channel is 
hanging up.

So my question is:  Is this how inbound calls from a switch need 
to automatically dial to a SIP channel, or does the call need to 
be answered in some other way, and then execute the Dial command?  
Does anyone please have any pointers, or example configuration for 
this kind of call scenario?

It is as if the signalling is not correct and the Harris is not 
getting some kind of wink signal when I try to Dial SIP, and the 
Harris hangs up the call, but when the demo playback executes, the 
Harris gets the right signal.  Can Asterisk actually debug the Zap 
channel to see where the call hangup is coming from, and if so, 
how?

Or maybe my zapata / zaptel configuration is not correct for this 
kind of call scenario.  Here is the relevant config:
zapata.conf:
context=Provider_T14
signalling=sf_featdmf
group=4
channel => 73-96

zaptel.conf:
span=1,0,0,esf,b8zs
#span=2,1,0,esf,b8zs
span=2,0,0,esf,b8zs
span=3,0,0,esf,b8zs
span=4,0,0,esf,b8zs

e&m=1-24
e&m=25-48
e&m=49-72
e&m=73-96