Where is a modem located?

Answer 1

In domestic home, it usually needs to be plugged in to a phone socket; so you will often find it near a phone.

In large commercial premises, if its a lan based modem, then its often locked away in a server room, or comms room. Wifi modems will need to be near the computers, so usually mounted on the ceiling.

Another Answer

If this is a question about MODEMs (MOdulator/DEModulator) at work, you should consult your network administrator.

Short answer - between your router and your ISP connection.

At home, there are some different types of modems you may encounter:

A phone modem (old technology) may be built into the chipset of the computer motherboard or will be a small card plugged into the backplane. This kind of modem will receive the four pin modular phone plug that plugs directly into the phone jack on the wall. It has a maximum baud rate of 56000 bits per second.

DSL modems are another type of modem you will find, if your phone service provider provides your internet access. These modems are small boxes of varying shape that interface between the phone network through a four pin phone plug, and with your router through a CAT5/6 cable (lookes like an 8 pin phone plug). This type of modem provides varous baud rates, usually determined by the physical distance between your house and the nearest switching station.

Cable modems are another type of modem you will find, if your cable service provider provides your Internet access. These modems are small boxes of varying shape that interface between the cable network through coaxial cable, and with your router through a CAT5/6 cable. These provide different baud rates determined by the data package you purchase from them.

There are optical ISPs, but I'm not familiar with their product lines.