[geeks] Modem Sniffer

[Sridhar Ayengar]

Lionel Peterson wrote:
>> Does anyone make a v.90/v.92 modem sniffer?  i.e. you plug your
>> modem into it, and then you plug it into your phone line and it
>> produces a copy of both the inbound and outbound data-streams?
> 
> I've not heard of such a device, and I'd have to wonder the benefits
> vs. capturing the conversation when the modem connects to the
> terminal device (terminal, modem, system, etc.)?

First of all, because the modem is a chip on the board, and the board is 
inaccessible.

> I've seen "taps" that allow you to monitor phone calls to an audio
> device (popular in IVRS shops to keep tabs on phone line
> usage/status), but I have to wonder how a three-way modem connection
> would sync up... As I understand it, the series of tones you hear
> before the modems consider themselves "connected" are negotiations to
> determine speed and feature sets supported.

I'm aware of this.

> Here is a link ot an organization that might be able to help (if your
> needs are great enough to warrant hiring out the job):
> http://www.skutchelectronics.com/

My needs aren't, but I'll take a gander at their website anyway.

> The only way I could see this working would be to have two modems
> connected back to back, and tap off the serial interconnect between
> the two...

That's something like what I was thinking.  I was just wondering if 
someone had something off the shelf before I actually go and kludge 
something up.  And lo, it would be kludgey!

> I'm curious about the application - mind sharing details?

Coming in private email.

Peace...  Sridhar