[Asterisk-Users] Norstar Integration with Asterisk via FXO or BRI ISDN

[Christopher Lee]

Hi,

I have a legacy Norstar system that I'm looking into integrating with my
Asterisk setup. 

My first attempts have worked, which involves a Wildcard X100P FXO card in
the * box connected to the Internal ATA (FXS port) on the Norstar system.

Calling from SIP -> Norstar works fine, since the SIP caller initiated the
call and generally will be sane enough to hangup the phone when complete,
making asterisk hangup the X100P.

However in the opposite direction, Norstar -> SIP, the problem begins,
thanks to no disconnect supervision/provision on the FXS port from the
Norstar, so the X100P doesn't know the Norstar caller has hangup.

A thought that occurred was perhaps Asterisk could do some sort of "soft"
disconnect supervision? So when the FXO card has seized the line, but there
is no transmit/receive audio (or no major variation from the standard
background radiation) then after a safe timeout of say a minute or two, it
could disconnect the line? I'd be interested to hear others views on this,
would it work (or does it already exist?).

Another thought is that the Norstar has both an 4-port FXO trunk card and a
4-port BRI-ISDN trunk card. The 4-port FXO card is completely free for use,
however it doesn't support disconnect supervision, so same problem there.

However, the BRI-ISDN card obviously does support disconnect supervision
_and_ Direct InDial, even better! Only two ports are in use, so I could
easily borrow one.