568A & 568B sending/receiving question

DerekAustin26

I understand hubs/routers/switches send on wires 3 & 6 and receive on 1 & 2 which is why they need a crossover cable to communicate between each other.

But what wires do pc's send on? Are they the exact opposite? Sending on 1 & 2 and receiving on 3 & 6?


Because if they didnt receive on 3 & 6 then how can they 'listen" for devices like hubs/switches & routers that send on those same wires?

My logic sounds correct but I just wanted to confirm because the book doesnt say what wires a pc sends and receives on. It just says what the devices send/receive on.

I appreciate anyone who could confirm this for me.

Thanks,

Plantwiz

I'm not sure I understand what you are looking for here.

Networks work because of the various protocols.

CSMA/CD protocol is a set of rules determining when devices respond. If the CSMA (carrier sense multiple access) /CD (collision detection) were not in place there would be data collision. Ethernet uses CSMA/CD to monitor the traffic and when no traffic is on the line, a device may transmit its signal. If there is a collision, the devices involve wait a period of time and transmit again.

DerekAustin26

Okay, you have your standard straight through cables and your crossover cables. Your straight through uses 568A on both ends. Crossover uses the 568B on one end which basically just means it crosses over wires 3 & 6 (orange & orange and white & green & green & white). Crossover cables send info on wires 3 & 6 and listen on 1 & 2 so they need to do a crossover for 3 & 6 to 1 & 2, if not they cannot communicate. So the question I have is...

"What wires do PC NIC's send & listen on? Obviously they cant send on 3 & 6 if they are using a straight through cable connected to a switch if switches listen on 1 & 2. So what wires do they send info on and receive on?

captobvious

Nics and Routers transmit on pins 1,2 and receive on pins 3,6
Hubs and Switches transmit on pins 3,6 and receive on pins 1,2

SysAdmin4066

I had an instructor years ago who always would say "router is PC" and it's true. There is absolutely no difference in the way the two work. If you wanted to connect two PCs, you would have to connect them via a xover. So they work just like routers, send and recieve on the same pins.