Signaling and Cabling

The cables used in various asynchronous connections differ depending on the end equipment
plus the type and distance of the connection.
Modems typically use two types of connectors—one for the connection to the host and one for
the connection to the phone network. An RS-232-C 25-pin connector typically provides the connection
to the host; the RS-232-C connector is also called an EIA/TIA-232 connector. Both terms
are still used today, although the EIA/TIA terminology is more current. A standard RJ-11 connector
provides the connection to the phone network.
For the connection between the DTE and the DCE, individual wires are used in the serial
cable. These wires and their functions are listed in Table 23.1.