Becasue of all the issues with fax over voip, we want to use pstn for our fax machine, but not dedicate a line just to fax. I'm thinking of having asterisk answer the pstn line, check for fax tones, and route appropriately. In zapata ( chan_dahdi ) set faxdetect=incoming then the dial plan would have [incoming-pstn] exten => fax,1,Dial(DAHDI/1) ; the fax machine exten => fax,2,Hangup() exten => s,1,Answer() exten => s,2,Dial(DAHDI/2) ; internal extension ............. Would this work? I'll need another TDM410 card to do this, so I'd like some reassurance before I go purchase it. sean
sean darcy wrote:> Would this work? I'll need another TDM410 card to do this, so I'd like > some reassurance before I go purchase it. >Yes, it'd work as long as Asterisk doesn't make a mistake on fax detection. From what I've read, it's sort of an art (Fax Detection that is). Doug -- Ben Franklin quote: "Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety."
On Sun, Oct 12, 2008 at 5:17 PM, sean darcy <seandarcy2 at gmail.com> wrote:> Becasue of all the issues with fax over voip, we want to use pstn for > our fax machine, but not dedicate a line just to fax. > > I'm thinking of having asterisk answer the pstn line, check for fax > tones, and route appropriately. In zapata ( chan_dahdi ) set > faxdetect=incoming > > then the dial plan would have > > [incoming-pstn] > exten => fax,1,Dial(DAHDI/1) ; the fax machine > exten => fax,2,Hangup() > > exten => s,1,Answer() > exten => s,2,Dial(DAHDI/2) ; internal extension > ............. > > Would this work? I'll need another TDM410 card to do this, so I'd like > some reassurance before I go purchase it. >Another thing you can do is get a "comswitch" -- they are pretty cheap and have been around for years. http://www.commandcommunications.com/products.php IMO they work pretty well. I use these as a backup. I use VoIP "only" at some sites and the fax line is used for the DSL. The comswitch is connected to the line and then connect the asterisk machine (using a cheap "winmodem"), fax machine and a red WECo 2500 clone. So if the DSL goes down the calls get routed through that phone line and the comswitch routes them to the Asterisk machine and the IP phones ring like normal. If the PBX goes down or the power for a long time, they can use the "Red phone" The main motivation for going to this setup was a low cost way to keep 911 working while trying to stay 100% voip . The comswitch was installed so in case 911 needs to call back it won't go straight to the fax. The use of the line as a backup ended up being an unintended consequence, but it seems to work well. This setup works very well, but if you are using this on a "main" phone line then be advised there will be an extra 1-2 ring delay -- the comswitch actually answers the call when it comes it and does fax detection. I also see these installed in many retail stores -- normally they will have 3 lines in a hunt group -- the 3rd line is shared between the fax and the hunt group using the comswitch.
On Sun, 12 Oct 2008, sean darcy wrote:> Becasue of all the issues with fax over voip, we want to use pstn for > our fax machine, but not dedicate a line just to fax. > > I'm thinking of having asterisk answer the pstn line, check for fax > tones, and route appropriately. In zapata ( chan_dahdi ) set > faxdetect=incoming > > then the dial plan would have > > [incoming-pstn] > exten => fax,1,Dial(DAHDI/1) ; the fax machine > exten => fax,2,Hangup() > > exten => s,1,Answer() > exten => s,2,Dial(DAHDI/2) ; internal extension > ............. > > Would this work? I'll need another TDM410 card to do this, so I'd like > some reassurance before I go purchase it.You need to Answer() the call first, then insert a Wait(2). During that time, asterisk will be listning for fax tone and jump to the fax extension if it hears them. So: exten => s,1,Answer() exten => s,n,Wait(2) Ringing() Dial(DAHDI/2) Hangup() and exten => fax,1,Dial(DHADI/1) exten => fax,n,Hangup() But at this point why not just feed it into RxFax? Gordon