Asterisk and PSTN / FXO


#1

Hi,

I have a working Asterisk server with SIP trunks. Now I want to use my PSTN line also with it.
I read everywhere that this configuration needs a special voice card named XP100.
I know that it’s not too expensive but I have too many idle external modems at home. Is it possible to use external modems as FXO card ?
I read different opinions on this issue but I couldn’t understand it well.

If it’s not possible than I will go and buy a XP100 pci card.
Please help me.

Thanks


#2

it is possible but not simple.
try equipment like lynksys pap2 (less then 80$, 2 fxo)


#3

PAP-2 is 2xFXS not FXO. The XP100 card will do what you want and is probably the cheapest. If you want to go with an ATA, the Sipura SPA-3000 will do what you want (1xFXO, 1xFXS).

p


#4

[quote=“p_lindheimer”]PAP-2 is 2xFXS not FXO. The XP100 card will do what you want and is probably the cheapest. If you want to go with an ATA, the Sipura SPA-3000 will do what you want (1xFXO, 1xFXS).

p[/quote]

yes I know PAP2 and SPA 3000 but I don’t want to use a external VoIP equipment for PSTN calls. I am already using the PAP2 for connecting my DECT phone to Asterisk via SIP. (and it is FXS only not FXO)

I just wonder if I can use my external 56K dialup/fax modems connected to the Asterisk server on serial port for this purpose. (dialing PSTN through Asterisk)
If that is possible my idle modems will have a use :smile:


#5

FWIW-
FXS connects to a phone. (fxS Serves the dialtone).
FXO connects to a Phone Line (telcO)

that said, your old modems will not help. First, asterisk used to support a few soft modems but no longer does, mostly because few used it.

Second, because you have the wrong modem. Serial cable modems do not have audio capability as a general rule. Even the internal ‘voice modems’ won’t work because many were real modems with sound card connections. What is needed is a ‘soft modem’, which is basically a sound card with a phone plug on the end (and a bit of extra circuitry for dealing with phone lines). This lets asterisk take full control over the line.

Yoru cheapest option is a clone Digium X100p card, which was a rebadged Intel Tiger Jet modem. THe Wiki has a bunch of info for how to find the right kind of modem, or easier, buy an x100 clone from any one of several voip vendors.

Hope that helps!


#6

[quote=“IronHelix”]FWIW-
Yoru cheapest option is a clone Digium X100p card, which was a rebadged Intel Tiger Jet modem. THe Wiki has a bunch of info for how to find the right kind of modem, or easier, buy an x100 clone from any one of several voip vendors.
[/quote]

Great information !
Thanks, it helps :smile:
I will order a xp100 clone from ebay right now :smile:


#7

My X100P clone card is on its way.
I wonder now if I can run the card through an Asterisk installed on a Virtual host (VMware)
is it possible to add the FXO card to my Virtual host in VMware ?


#8

I highly doubt it.