[Asterisk-Users] Channel banks, voicemail, and immediate=no

[Chris A. Icide]

When using a channel bank for analog handsets, you have a couple options in 
the way you handle transactions involving the analog handsets and origination.

With immediate set to no, it appears to me that soon as a digit is pressed 
after going off-hook, the single digit is taken and processed against the 
context that the channel is associated with from the configuration in 
zapata.conf.

With immediate set to yes, the extension s in the channel's context is 
processed.

As far as I know, the method of handling channel bank based analog handsets 
is to use immediate=yes and then have extension s put the phone directly 
into a DISA command with no-password and a context for processing the 
entered calls.

I have also tried in the past setting immediate=no, parsing off the first 
digit and sending the call into separate contexts (see example below)

example with immediate=yes

exten => s,1,DISA,no-password|internal


example with immediate=no

exten => 9,1,DISA,no-password|pstn-gateway


In the first case, the problem I have is this:  If I place the handset 
directly into DISA, how can I get stuttertone MWI indication?

If I use the second method, in many cases, there is NO dialtone provided to 
the phone until after a dtmf entry is recieved.  This I suspect is a 
channel bank issue because it seems to work on some banks, and not on others.


Given the use of channel banks as a method to allow large number of analog 
phones to access an asterisk system, is there any way (or perhaps any 
interest in developing a method) to actually treat analog handsets on a 
channel bank like any other UA?  In other words, why not have a method 
besides the two above so that I can stick the phones into a context (which 
understands it's for handling analog phones on a channel bank) that 
actually provides dial tone, and accepts dtmf until a match to the context 
extensions is found?  In other words, with immediate=no, I'd like to see 
asterisk not jump on the first dtmf and try to match (going to i, if no 
match exists), but actually wait for as many dtmf's as required to match an 
extension in the context (e.g. exten => _1NXXNXXXXXX waits for 10 digits if 
dtmf 1 is the first digit).


On a different track, am I doing something wrong above?  For people who 
have configured channel banks for use with asterisk, have you found a 
'perfect' configuration that you prefer to use?

-Chris