[asterisk-users] Problem with busydetect and cell phones

Trevor G. Hammonds trevor at concipient.net
Mon Feb 19 01:22:11 MST 2007


> Ryan McDaniel wrote:
> >> I have a very strange problem I'm hoping someone has encountered
> > already.
> >> I've scoured the internet for an answer to this one.  My phone
> company
> >> provides no disconnect supervision.  Hence I'm forced to use the
> > busydetect
> >> feature.  I have a TDM400 with two FXO ports.  If I call from an
> > internal
> >> extension to a landline and then hangup the landline Asterisk
> detects
> > the
> >> busy signal correctly and clears the line.  If I call from an
> internal
> >> extension to a cell phone and then hangup the cell phone Asterisk
> will
> >> never
> >> detect the busy signal though it is clearly there.  Asterisk will
> > happily
> >> sit there listening to the busy signal.  I suspect that the busy
> signal
> >> styles are slightly different though it is undetectable to me.  How
> can
> > I
> >> fix this???  It causes severe issues when a call is forwarded to a
> cell
> >> phone via the Zap interfaces as once you hangup the cell phone
> Asterisk
> >> never releases the channel.
> >>
> >
> > The landlines are with AT&T.  The cell phones I'm testing with are
> > Cingular (AT&T subsidiary).  There must be a subtle difference in the
> > busy signals.  How can I make it catch busy signals from both
> carriers?
> 
> Have you tried calling AT&T and asking for call disconnect supervision?
> 
> I realise that this can be a thankless and tedious endeavour, but it IS
> worth trying. There are almost no commercial switches that don't
> support
> this; it's a matter of activating it for the specific circuit in
> software. Particularly if you have a business line -- you can demand
> it.
> All PBXs need it if they use analog lines (and plenty still do) so I'm
> sure this is not an alien concept to AT&T. It's just a matter of
> finding
> the right Earthling there who can help you.
> 
> This might be one of those times where a "beer with the technician"
> will
> get you some joy, if calling Repair doesn't give you any joy.
> 
> -Stephen-
> 
> 
> Unfortunately I tried that.  Apparently my lines are on one of the last
> really ancient junction boxes in Southern California.  When using
> busydetect is it looking for any on / off repetitive sound to identify
> the busy signal, or for a specific length sound as defined in the
> indications.conf region?  I'd really like to avoid using callprogress
> if
> possible.  Is there a way to tweak it so it will accept a wider variety
> of busy patterns?
> 
> - Ryan

Ryan,
Even 1AESS switches offer disconnect supervision -- and I am not aware of
any of those still in primary service in Southern California.  By early
2000, Pacific Bell (then SBC, now AT&T) replaced all the analogue 1As with
DMS-100s.  If you care to contact me off list, I may be able to help get you
in touch with the right department to assist you.

		Sincerely,
		Trevor Hammonds






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