Christopher Tengi <tengi@princeton.edu> (05/07/91)
Can anybody out there post the definitive method of pairing (with
color code) for the AT&T PDS scheme? I saw a post in comp.dcom.lans
that gave the following diagram:
WH OR WH BL WH GR WH BR
OR WH GR WH BL WH BR WH
(RJ-45F) 1 2 3 4 5 6 7 8
| | | | | | | |
pairs: T2 R2 T3 R1 T1 R3 R4 T4
+--+ | +--+ | +--+
+--------+
The trouble I have is with pair 4. Which pin is really tip, and
shouldn't it be white/brown? Also, is pair 2 really on pins 1 and 2,
or is it on 3 and 6?
Thanks,
Chris
UUCP: ...princeton!tengi VOICEnet: 609-258-6799
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BITNET: TENGI@PUCC"Barton F. Bruce" <Barton.Bruce@camb.com> (05/09/91)
In article <telecom11.340.3@eecs.nwu.edu>, tengi@princeton.edu (Christopher Tengi) writes: > Can anybody out there post the definitive method of pairing (with > color code) for the AT&T PDS scheme? I saw a post in comp.dcom.lans > that gave the following diagram: > WH OR WH BL WH GR WH BR > OR WH GR WH BL WH BR WH > (RJ-45F) 1 2 3 4 5 6 7 8 > | | | | | | | | > pairs: T2 R2 T3 R1 T1 R3 R4 T4 > +--+ | +--+ | +--+ > +--------+ > The trouble I have is with pair 4. Which pin is really tip, and > shouldn't it be white/brown? Also, is pair 2 really on pins 1 and 2, > or is it on 3 and 6? For AT&T 258A, your problem may be that R4 and T4 labels are reversed, but the wire colors are in the right places. Possibly there is confusion with the USOC punchdown where 7 and 8 are R3 and T4 respectively. 7 and 8 are T4 and R4 respectively for BOTH AT&T 258A and EIA. The issue of pair 2 possibly being on pins 3 and 6 is probably raised because EIA in their 'wisdom' (read: PERVERSITY) won't use AT&T's exact punchdown. Their pairs 2 and 3 are swapped from the AT&T plan. Sillyness bound to cause grief. Perhaps EIA's choice has a tad more horse sense, simply because having pair 2 on pins 3 and 6 then lets that pair exactly match USOC. You HAVE to be paranoid about every adapter or harmonica or whatever. It MUST be wired to match whatever installation it is going into. If it is a site without tight control by knowledgable folks, and various vendors have been adding things over the years, LOTS OF LUCK. Here is your diagram 'repaired' for 258A. WH OR WH BL WH GR WH BR OR WH GR WH BL WH BR WH 1 2 3 4 5 6 7 8 | | | | | | | | pairs: T2 R2 T3 R1 T1 R3 T4 R4 +--+ | +--+ | +--+ +--------+ And for EIA: WH GR WH BL WH OR WH BR GR WH OR WH BL WH BR WH 1 2 3 4 5 6 7 8 | | | | | | | | pairs: T3 R3 T2 R1 T1 R2 T4 R4 +--+ | +--+ | +--+ +--------+ And for USOC BR WH WH BL WH OR GR WH WH GR OR WH BL WH WH BR 1 2 3 4 5 6 7 8 | | | | | | | | pairs: R4 T3 T2 R1 T1 R2 R3 T4 | | | +--+ | | | | | +--------+ | | | +--------------+ | +--------------------+ Now someone will probably claim that 258A in not what AT&T is using for PDS!