cat5 cable FREE cabling and networking Helpdesk
 Question by jon zivku posted 20 Oct 2005
 cat5 cable
Is it possible to use on a rj-45 ethernet plug /cat5 just 1 pair for internet connection? And which pair is it on T-568b
 Answer by Joseph Golan posted 20 Oct 2005
Dear jon,

The answer is yes and no.

First for the yeses -

1. If you are talking about via DSL (modem) or similar signal, it uses the same pair that your telephone line is on and it would connect to the input of the DSL modem, the output of the DSL modem (Ethernet would connect to your PC via a NIC. The pair on a T568B wired jack would be pair 1 (Blue/White)

2. If you are talking about using a dial-up modem, the telephone line would normally be on pair 1 (Blue/White) of a T568B wired jack

Now for the NO

If you are talking about an ethernet type connection it would require a minimum of 2 pairs, pairs 2 & 3 (Orange/White & Green/White) for either 10BaseT or 100BaseT type ethernetand all four pairs for 1000BaseT ethernet.

Joseph Golan, RCDD

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