CAT 5: 4-Pair usage

They are used for an additional transmitter and receiver at each end of the cable. Each transmitter and receiver uses two wires. The 100BASE-T4 and 1000BASE-TX uses the same pin-out and color code standards as the 100BASE-TX and 10BASE-T for straight-thru cables. One would cross the other two pairs for 100BASE-T4 and 1000BASE-TX standards in addition to the first two pairs used(!) 100BASE-TX and 10BASE-T (See http://duxcw.com/digest/Howto/network/cable/cable1.htm). 100BASE-T4 is nearly dead. If you would like, draw me a picture after reading the article and I’ll tell you if it’s correct. It should be rather obvious. Larry

3. RE: CAT 5: 4-Pair usage
Sam Guo Mar-21-02 12:46 PM
In response to message 2

You said thant Each transmitter and receiver uses two wires.
It it "two wires" or "two pairs". I guess that for1000Base-TX, it means "two pairs".
Am I correct?

If each Tx uses two differential pairs, it means that there are two Tx+ and two Tx-, 4 wires in total.
For the same token, If each Rx uses two differential pairs, it means that there are two Rx+ and two Rx-, 4 wires in total.
Am I correct?

If the above is the case, do you have any idea about how signals transfer through Tx1+, Tx1- and Tx2+, Tx2- at the same time and how signals are received through Rx1+, Rx1- and Rx2+, Rx2- at the same time?

4. RE: CAT 5: 4-Pair usage
lbyard Mar-21-02 01:31 PM
In response to message 3

I said wires and I meant wires. Please read the article in my last post before asking more questions. Look at the diagram in A Little Theory. Larry