[SOLVED] Ethernet Wiring Problem

I moved to a new building and noticed, the Wired Network connectivity was under performing (Wireless speed is as expected - 250 Mbps).
On further investigation I found the connection from the Patch Panel to the wall socket of the room(I'm working on) was not correct. The Ethernet wiring is not correct. Please check the attached drawing.
My question is How is this connection working at all? Because both the pairs 1,2 and 3,6 are wrong. Only 4 and 5 are correct. I am receiving speeds upto 100Mbps (both Downlink and Uplink).
My guess is - My PC having gigabit Ethernet port is using the the pair 4,5 for data Tx and Rx, and that is the reason why my speed is limited to 100 Mbps. Please correct me if I'm wrong. Any thoughts on how it works is appreciated.


Vyas G.

Most Gbit capable (1000BASE-T) interfaces have auto crossover feature for 10/100-Mbit connection, they can connect with the cable shown above. If at least one peer (switch or PC) has Gbit interface, you can use straight or crossover cables as well. The feature is optional according to IEEE 802.3, and it can be disabled in the PHY configuration.

On the other hand a GBit PHY can have additional features, e.g. correct any channel order error beside standard MDI and MDI-X configuration. Not sure if some can even run 1000BASE-T mode over less than four pairs.

FvM said:

Most Gbit capable (1000BASE-T) interfaces have auto crossover feature for 10/100-Mbit connection, they can connect with the cable shown above. If at least one peer (switch or PC) has Gbit interface, you can use straight or crossover cables as well. The feature is optional according to IEEE 802.3, and it can be disabled in the PHY configuration.

On the other hand a GBit PHY can have additional features, e.g. correct any channel order error beside standard MDI and MDI-X configuration. Not sure if some can even run 1000BASE-T mode over less than four pairs.

Click to expand...

Thank You. I am shocked why I did not see this. The cabling in the wall is just a crossover.