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<DIV><FONT face=Arial size=2>We have a VG248 and were told by Cisco to use one
of the aforementioned adapters for call supervision. Only after did I find
out that that VG248 has the following Call Supervision modes: </FONT><FONT
face=Arial size=2>drop loop current, reverse polarity. Would either of them
worked in out situation? Who knows. Something to consider, however.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=josmon@rigozsaurus.com href="mailto:josmon@rigozsaurus.com">John
Osmon</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=cisco-voip@puck.nether.net
href="mailto:cisco-voip@puck.nether.net">cisco-voip@puck.nether.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, October 28, 2005 5:25
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [cisco-voip] Intercom in
Callmanager</DIV>
<DIV><BR></DIV>On Fri, Oct 28, 2005 at 02:21:41PM -0500, Schuett, Court (MBNAP
it) wrote:<BR>> That's what we did. We ran from an ATA 186 port into
the amplifier that ran<BR>> into the speakers. We had a wiring
company set up the amp and speakers for<BR>> us. It was pretty simple
and it sounded like they had done it before.<BR>> Connecting it to the ATA
was also very simple. Just assigned the ATA a<BR>> number and when
people want to announce over the speakers, they just call<BR>> that
number. There was a catch to it though. When the number was
called,<BR>> the speakers would pick up, but they wouldn't let go.
What happened was the<BR>> person would call, make the announcement and
then hang up. But the speakers<BR>> would still be broadcasting and
would eventually go to a busy signal. To<BR>> fix this, you have to
go in and change the polarity on the ATA to 0x00008 I<BR>> believe.
Might want to call TAC and confirm that though.<BR><BR>Classic disconnect
supervision problem. When you have an analog line<BR>it is difficult to
tell something at the other end that the call is<BR>over. (Humans are
easy -- the 'goodbye' protocol signals the end of<BR>the conversation, so they
hang up.)<BR><BR>Disconnect supervision on analog lines is typically handled
by:<BR> - shorting the line (removing voltage)<BR> - reversing
polarity of the line<BR> - playing special tones (rare)<BR><BR>Don't
forget that the end device has to support that particular<BR>disconnect
supervision as well...<BR><BR>Last I'd heard is that the ATAs have *NO*
disconnect supervision, but if<BR>you've gotten them to break with the
speakers, obviously *something*<BR>is working. Thanks for the
tip.<BR>_______________________________________________<BR>cisco-voip mailing
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