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Hi

I browsed through the archives, but didn't find a very good
explanation as to why we can't use a good voice modem as FXO card for
small setups (read: cheap).

Is it because their CODECs suck, or they don't support enough of them?

Thanks.

"John Doe" <> wrote in message
news:...
----- Original Message -----

> Hi
>
> I browsed through the archives, but didn't find a very good
> explanation as to why we can't use a good voice modem as FXO card
> for small setups (read: cheap).
>
> Is it because their CODECs suck, or they don't support enough of them?

As far as I know, most (all?) voice modems are half-duplex: they can send
or receive voice, but can't do both things at the same time. Moreover,
their codecs are usually based on some variant of ADPCM, and the driver
should transcode the data into some other format suitable for VoIP. All in
all, it's just not worth the trouble.

On the other hand, some Winmodems (or Linmodems, if we prefer a
Penguinically-correct designation ), i.e. data modems where the data
modulation/demodulation is offloaded to the CPU, can be adapted as FXO
cards just rewriting their software drivers. This is not trivial
(requiring the knowledge of the specific hardware) but was done by Digium
for two models, one based on a Motorola chipset and another on an Intel
chipset. They used to be sold under the names "x100p" and "x101p"
respectively. Digium has now discontinued them, but there are still
several third-party vendors of compatible hardware: just check the hits at
http://www.google.com.hk/search?q=x100p .

See also: http://www.voip-info.org/tiki-index....ge=X100P+clone

Enzo

On Mon, 1 May 2006 15:27:30 +0800, "Enzo Michelangeli"
<> wrote:
(snip)

Thanks for the links. I'm about to order a couple of those X10?p cards
for my first test Asterisk setup, and see how they fare.

> See also: http://www.voip-info.org/tiki-index....ge=X100P+clone

IMHO, most clones can't display the incoming call's callerID.



--
Raqueeb Hassan
Bangladesh

On 1 May 2006 10:28:35 -0700, "Raqueeb Hassan" <>
wrote:
>IMHO, most clones can't display the incoming call's callerID.

Uh-oh... That's an important feature :-/

Does someone know about real clones as advertised on eBay
(http://search.ebay.com/fxo-asterisk), such as...

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9719116318
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9718408471
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9720092845
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9718298351
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=9718788040

Thank you.

I dont think its impossible. I read somewhere that Intel 537 chipset
modems can function as an FXO. But I havent tried that out myself.
But at the moment I have sucessfully used a hardware modem (not a
softmodem) as a full duplex VOIP-PSTN gateway, that can route calls.
(Usually the modem's audio driver is half duplex.)


Rochana

On 1 May 2006 15:58:15 -0700, ""
<> wrote:
>But at the moment I have sucessfully used a hardware modem (not a
>softmodem) as a full duplex VOIP-PSTN gateway, that can route calls.
>(Usually the modem's audio driver is half duplex.)

Cool. Reference? Support for caller ID?

DLink DFM562I is the modem. There is a good AT command reference in
their website
http://www.dlink.com.au/tech/Downloa...letype=Manuals
The manual says Caller ID is supported. But I havent checked that. I'm
only using it for outbound dialling.

On 1 May 2006 19:16:59 -0700, "Rochana N" <> wrote:
>DLink DFM562I is the modem.

Thx.