Path: utzoo!telecom-request Date: Sat, 25 May 91 12:19 PDT From: John Higdon Newsgroups: comp.dcom.telecom Subject: Re: Why a Twist in Modular Cables? Reply-To: John Higdon Message-ID: Organization: Green Hills and Cows Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 396, Message 5 of 6 Lines: 24 rees@pisa.citi.umich.edu (Jim Rees) writes: > Every ready-made RJ-11 cable I've ever seen has the plugs attached on > the same side of the cable at each end. > So is there a reason for it, or is it just manufacturing convenience? Yes and yes. Bulk cable (for putting the ends on yourself) has a ridge on one side. By standardizing which way the ridge goes into the crimper, it is easy to accurately and speedily put modular plugs on the cable without worrying about whether you have "end A" or "end B" in your hands. Modular receptacals come in two flavors: receptacal and instrument. There is an assumption of pair rotation between the two, hence the tip (green) and ring (red) will match at their respective ends, regardless of the actual color of the conductor in the cable, which can vary depending on which way it is "facing". John Higdon | P. O. Box 7648 | +1 408 723 1395 john@zygot.ati.com | San Jose, CA 95150 | M o o !