scott@eddie.MIT.EDU (Scott Statton) (09/24/88)
Netlanders: I submit this definition of the wiring of RJ-11, RJ-18, and RJ-14 devices, as specified at 'the horses mouth'. Quoting from Title 47 CFR, Chapter I (October, 1986) [Federal Communication Commision] Section 68.502, "Configurations" [begin quote] USOC RJ-11 -- Bridged T/R; 6 position jack. Single Line Bridged tip and ring only -- conductors 1, 2, 5, and 6 are reserved for telephone company use. RJ-11W for wallmount, RJ-11C for all others. pinout 1 -- reserved 2 -- reserved 3 -- RING 4 -- TIP 5 -- reserved 6 -- reserved USOC RJ-18 -- Bridged T/R with make-busy arrangement; 6 position jack. Single line bridged tip and ring only with MB/MB1 leads. Conductors 2 and 5 are reserved for telephone company use. RJ-18W for wall mount, RJ-18C for all others. pinout 1 -- MB 2 -- reserved 3 -- RING 4 -- TIP 5 -- reserved 6 -- MB1 note: when MB and MB1 are shorted, the line will show as artificially busy. USOC RJ-14 -- Two-line configuration Bridged T/R; 6 position jack. Two line bridged tip and ring. RJ-14W for wall mount, RJ-14C for all others. pinout 1 -- reserved 2 -- TIP 2 3 -- RING 1 4 -- TIP 1 5 -- RING 2 6 -- reserved [end of unauthorized quote] Note that the CFR goes on to describe several other connectors that are not related to this discussion. I will not insult the net with a poorly drawn ASCII graphic showing the connectors physical layout -- look at a modular plug for youself. The pins are numbered from left to right, 1 through 6. NB -- on many cordsets for residential installation, contacts for pins 1 and 6 are missing for economy. On a smaller proportion, pins 1, 2, 5, and 6 are missing. Note also, that the CFR describes A/A1 signalling, where pins 2 and 5 are used to signal PBX systems for two purposes. One: That the given extension is in use, two: to signal that the given conversation is to be placed on 'hold'. It neglects to mention the pinout of the RJ-12 and RJ-13 jacks used for this system. * sigh *. -- ------------------------------------------------------------------------------ scott@eddie.mit.edu | I don't have any opinions. ------------------------------------------------------------------------------