06-19-2009 07:12 PM - edited 06-19-2009 07:17 PM
My Intel onboard ethernet adapter reports that my ethernet cable polarity is reversed. If I bypass the WRT610N router and hook directly to my Motorola SB6120 modem, then the polarity is normal with ALL my cables.
Why does the WRT610N reverse ethernet cable polarity????
EDIT: Seems like polarity shows as reversed when running in gigabit mode. If I run in 10/100 mode, then the polarity shows normal. Whats up with that?
06-20-2009 01:47 PM
The Gigabit Ethernet standards committee selected 8B/10B transmission coding for the physical coding sublayer...
The 8B/10B conversion is an encoding scheme employed especially in Gigabit Ethernet such as 1000BASE-LX, 1000BASE-SX and 1000BASE-CX or in Fiber Channel, wherein a pattern is selected from within the 10-bit code space so that 0s and 1s may be almost equal in number, and 8-bit code is converted to 10-bit code for transmission and vice versa for reception.
When converting 8-bit data to 10-bit data, the balance of the 0s and 1s contained in the data is suitably adjusted to thereby enable recovery of the data signal with reduced bit error rate as well as recovery of the clock signal embedded in the data signal...
Hope this helps...
06-22-2009 11:20 AM
My other computers are wireless.
I was simply using the Intel network adapter diagnostic tools and noticed that it reported reverse polarity. Again, if I bypass the router and run straight from my cable modem (with the same ethernet cable), then the polarity is normal. I have tried multiple cables, so I am lead to believe that the router is the culprit.
06-23-2009 11:18 AM
06-23-2009 01:45 PM
I would, but my laptop does not support gigabit ethernet and even if it did, it does not have an onboard Intel adapter that has the polarity testing feature.
What is really weird is when I change my desktop to work in 10/100 mode. The polarity shows as normal then.
Soon as I change to gigabit mode, the polarity shows reversed.
I just want to know if this is normal behavior.