Hi Imranraheel:

Yes, such a device is very possible--they're in labs on every Cisco campus and countless thousands of other locations around the world.  The old 2500 series routers were extremely popular to use for these purposes, although just about any model router with asychronous interfaces can be used.  Typically the router has several async serial interfaces that get broken out by an octal cable and connect to the console ports of routers and switches in multiples of 8.  A modem can then be attached to another serial interface and connected to a modem and phone line.  I would think that most partners and resellers would be very familiar with the concept and help you put together one sized appropriately for your needs.  An inbound connection gets re-routed to the device by doing a reverse telnet over one of the serial lines connected over the octal cable links.

Sincerely,

Rollin Kibbe

Network Management Systems Team