multiple voice over Cat 5 FREE cabling and networking Helpdesk
 Question by Todd Jackson posted 12 Dec 2004
 multiple voice over Cat 5
I have a small office with 2 Cat5e cables pulled to each workstation. One will be used for data and the other is to be used for phones. The phones will have either one or two lines. The lines from the phone company terminates in a patch panel. The two-line phones have one 4 conductor cords. To force the two lines over the Cat5 cable I am using an adapter with two female plugs, one with 2 conductors and one with four, and a male plug with four. I is supposedly designed for this purpose. The problem is when I plug the two line phone in at the far end, I only get dialtone for one line. If I switch the order on the lines going into the adaptor I get the other line. If I plug another adaptor of the same type in the jack at the far end to split back to two separate connections and test each port with a single-line phone, both lines come through. Any help on resolving this would be greatly appreciated.
 Answer by Dmitri Abaimov posted 17 Dec 2004
Dear Todd,

If the CAT5E jacks were wired using T568B pin layout, it will not work this way because the four central pins inside RJ45 will form pairs #1 and #3, not #1 and #2 as needed for the adapters you are using. You can remove the jack and re-wire it for T568A. It is especially easy if it is a tool-less jack and it has a color-coded pinout guide inside. Otherwise you'll have to get yourself a punch-down tool. Here is the color code for your reference:

Good luck!

Dmitri Abaimov, RCDD

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