Hi,

Let's start from the end.
Yes I know iReady. I purchased a development kit from Seiko, I mean the ISA board with two S7600 fitted on board. Very nice piece with good technical support from iReady. I've just play with Atmel 89C52 connected to the S7600 spare one on the breadboard area. I'll try to take some pictures and send it to you. I don't have now a web page but soon as I'll be ready with my serious research I'll build one.
Later I discovered the IMM development kit, which I didn't succeed to get one until now. However I'm not too much eager to purchase, since connects only at 2400 bps.
If you are interested, you can find another Connexant compatible modules with TCP/IP and dial up modem included on the same small board at:
http://www.edevice.com/content/solution/modem.htm
http://www.connectone.com/html/imodem.htm
You can easy attach these kind of devices to MCS51 series, much easier than S7600. Obvious, you must shake your wallet.
But the real chalenge is to have your own TCP/IP stack.
After huge digging inside protocols and a lot of help from Scenix iSX Web Server and eSX E-mail Appliance Demo Board I'm on my way to develop for my own purpose, not to be included or sold in a product. Just to proove myself I can do it. Don't request now. I'll share my knowledge, freeware with others when I'll be ready and sure that the code is working. Not in C, but in assembler and not with such large aplication spectrum as CMX stack is. Only PPP, SMTP, POP3 and HTML. I'm not interested at all to Ethernet as link layer, because I don't like the home appliance linked to the internet through nearest PC station or server. I prefer modem or GSM.
One last hour news :
Is it possible to push up an ordinary 8/16-bit based system with limited memory resources to function as a webserver and so be able to provide it's user interface inside a browser window ?
This question belongs to http://www.micro-webserver.com/
It worth take a look.

You wrote:
"I didn't found how to connect an oridinary PC modem via serial RS232 to the uC system"
Easy, as PC is doing. If you find a suitable RS232 communication spy it will became as easy as you watch your neighbour undressing at opposite window.
You wrote:
"In the first step I have tried how software handshake has worked. But I am not quite sure if it was good for my modem"
I think I know what bother you. If you look at the 25 or 9 pins outside modem socket with RTS, CTS, DTR, DSR, RI, CD you can't figure out how modem will understand XON, XOFF through RX, TX lines especially when he is ready listening to hardware hanshake. I encountered the some problem when I change my Cermetek CH2100 (exclusive software handshake) to embedded Multitech.
Well, look at the ampersand (&) commands : &Dn, &Hn, &In, &Rn, &Sn. You can see a lot of references to Hayes commands, but not too much details about them. I'll try these quiet christmas days to clean my code concerned to modem communication and send it to you. The main job is to translate the comments from romanian language to english. And are a lot of comments.


Regards,
Silviu