On Mon, 2008-01-21 at 12:16 -0600, Mikkel L. Ellertson wrote: > Mikkel L. Ellertson wrote: > > I could have sworn that the CAT 3 cable I used for networking was 4 > > pair, and not 2 pair. I can remember some 2 pair cable use for POT > > connections, but every networking application was 4 pair. Now, both > > 10BaseT and 100BaseTx only use 2 pair, but the cable is normally 4 pair. > > Now, there is a difference a physical difference between CAT 3 and CAT > > 5, but it has more to do with how the pairs are twisted together then > > the number of wires. The number of wists/inch, and the relationship > > between the number of twists in each pair change the electrical > > characteristics of the cable. (Each pair has a different twist rate.) I > > think how the pairs are twisted together in the cable is also specified. > > > Not enough coffee - Both CAT 3 and CAT 5 cable are available in > different number of pairs, but 4 pair tends to be the most common in > CAT 5 and CAT5e. You want to have fun, try terminating a 100 pair > CAT 3 cable. At least with CAT 5, they tend to bundle each set of 5 > pair in their own jacket inside the main cable. (I would rather have > them bundled in 4 pair groups - I hate wasting 5 pair of a 25 pair > cable when doing networking. I would rather have 5 groups of 4 pair > for a 20 pair cable.) Most CAT5e 25-pair I've seen don't bundle five pairs in a separate jacket...it's just a standard 25-pair telco cable that meets 5e specs (and I've even seen CAT6 versions of the same cable). I've used the 5e stuff a BUNCH of times...typically to cross-connect racks using 24-port patch panels. Each panel requires four 25-pair cables and you sacrifice a single pair per 25-pair cable. I've pushed gigabit across it with no problems--I've even pushed 10GB across it with a bit less success (haven't tried the CAT6 version, but I don't design data centers much anymore). > > Mikkel > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list ---------------------------------------------------------------------- - Rick Stevens, Principal Engineer rstevens@xxxxxxxxxxxx - - CDN Systems, Internap, Inc. http://www.internap.com - - - - Never test for an error condition you don't know how to handle. - ----------------------------------------------------------------------
