e best transmission. The Telecom Handbook 249 CABLE The 8-pin connector is larger than the 6-pin. There is also a 4-pin connector that is the same size as the 6-pin connector, but only four wires are terminated on it. There are also different standards in use which dictate differ- ent ways for terminating the cables. Two standards. EIA-TIA 568A and 568B specify two different methods of wiring the jacks for the 4-pair cables as a part of the overall standard. The jack for the telephone in your home is probably a 42A block (if the tele- phone is hardwired into it) or an RJ11C if the telephone plugs into it with a modular connector (6 pin). The RJ11C jack is a little beige square plastic box into which a 6 pin modular connector is plugged (the type of plug at the end of the mounting cord on a single-line telephone). This connects the telephone to the wires which in turn connect you through the cable in your home, out to the street, and back to the central of- fice of the local telephone company. There your call goes through switching equipment (the central office switch) to be connected to the telephone number you are calling. Your voice then travels in the same manner out to the telephone at the other end. The term quad was used to refer to an older type of 2-pair cable. It was not twisted and is no longer used in new installations (quad uses 4 wires, one pair red/green and the other yellow/black). In what was formerly The Bell System, the division known as Western Electric developed some standard wiring configura- tions for jacks used today. The two most commonly encountered are RJ11C (6 pin modular jack) and RJ45 (8 pin modular jack). RJ stands for registered jack. In new installations it is increas- ingly rare to see RJ11C jacks since RJ45 is becoming the standard. Many offices run four separate 4-pair cables to the desk, ter- minating each in a separate jack (Figure 12.2). One of these jacks may be used to plug in the telephone. Another may be used to plug the computer into the LAN (local area network). A third