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Malcolm Taylor wrote:<br>
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<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">I have connected my home
phone line into my asterisk box via
an X100P, but have noticed that asterisk doesn’t check the line for
dialtone before dialing, barging in on any non-asterisk call which is
taking
place.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">I see from the
voip-info.org wishlist that there is an
outstanding item to ‘</span></font><font color="black" face="Verdana"
size="1"><span
style="font-size: 9pt; font-family: Verdana; color: black;">Listen for
dial tone
before dialing’ and I also see someone suggesting a solution for the
problem by adding additional hardware into the home phone circuit.</span></font></p>
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</blockquote>
What it SHOULD do is, check the DC voltage on the line, and if less
than 8-10 volts, consider it BUSY/ unavailable/not connected, THEN
check for dialtone before dialing. Also optionally listen for stutter
dialtone before dialing, making the detection of stutter dialtone
available for some other action.<br>
Certainly these days even simple key/hybrid PBX switches monitor the DC
status before allowing access to a line.<br>
<br>
John Novack<br>
<br>
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