[asterisk-dev] Routing data modem calls

[Olivier Krief]

----- Original Message ----- 
From: "Brian Candler" <B.Candler at pobox.com>
To: "Olivier Krief" <olivier.krief at gmail.com>
Cc: <asterisk-dev at lists.digium.com>
Sent: Friday, July 28, 2006 3:05 PM
Subject: Re: [asterisk-dev] Routing data modem calls


> On Fri, Jul 28, 2006 at 12:49:14PM +0200, Olivier Krief wrote:
>> In many cases, I noticed (though I didn't experienced) data modems could
>> simply be replaced by serial-to-ethernet converters plus dialup routers.
>> What do you think of that ?
>
> That won't work for me:
>
> (1) EPOS terminals may have modems built-in. It would require 
> modifications
> to the terminals to get at the RS232 signals.
I totally agree with you : if you have a built-in modem and no way to use 
another communication port (which obviously could be the case with some 
terminals), you have find a way to transport modem signals.

>
> (2) The other end (i.e. the bank or whatever) would also need to install
> serial-to-ethernet convertors, in addition to their existing modem bank.
> Then I would need to install a secure IP link into the bank or whatever,
> whereas at the moment all these calls just come in over the PSTN.

I was thinking of this case :

Instead of :
Terminal --- Data Modem ---- PBX ---- PSTN -----Modem Bank ---- Whatever

Use this :
Terminal --- Serial-to-Ethernet ---- LAN ---- Dialup router ---- PSTN ----  
Modem Bank ---- Whatever

In the latter situation, you can concentrate several terminals spread on 
different locations with a single router (and then cut several TDM lines to 
PSTN). And when the other side (i.e. the bank or whatever) moves to IP, 
changing the router is enough.

I met this case with legacy Payment Terminals which have a built-in serial 
port and a FXO port while new ones (and high end) now have a built-in 
Ethernet port.

>
> Regards,
>
> Brian.