VOIP FAX

I only have a single CAT-5 cable coming into my office, so it was easy to conclude that I should use all the wire pairs for ethernet, and set up a VOIP system. I use Asterisk, the open source telephony project, to run a couple of SIP phones (Polycom 501) on our desktops. I still connect to the PSTN using a Digium TDM-400P analog telephony card, because I’m not ready to entrust all of our voice traffic to the internet (especially at the premium prices charged by the IP telephony providers.

Yesterday I needed to send a fax, but the multifunction printer for fax/print/copy/scan that I already wrote about wasn’t working. Although this has ethernet, it does not support SIP, so I have to use its POTS connection. That was a problem that I solved with a Linksys PAP2/NA ATA.

Anyway, the fax wouldn’t go through. First I though I must have misconfigured something in asterisk, so I opened up the  asterisk console for debugging. And of course I started tweaking configurations at the ATA, and within Asterisk’s dialplan and sip configuration –to no avail. Finally I plugged in an analog phone and got no dial tone. More fiddling without luck. So I went into my wiring closet, and found no dial tone. Hmmm… I went out to the MPOE, and found no dial tone!!!

No wonder we haven’t been getting nuisance faxes. Judith had complained that the fax wasn’t working, but I just assumed it was in the software, and since it wasn’t my problem, I ignored it. Well AT&T came out today and reconnected the line — someone must have lifted our fax wire pair some time ago, and I never paid attention.

The good news is that it works, at least outbound. I wonder how long before the spam faxes start up again?

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