Additions:

• 1000Base-LX
  • fiber cabling
  • 5km cable length
• 1000Base-ZX
  • support 70km cable length

Cabling

Types

• half-duplex
  • a port cannot send and receive data at the same time
  • only one device is allowed to send data
  • Use for collisions
• full-duplex
  • multiple devices are allowed to send data
• simplex
  • only one direction

Collisions:

• there are collision domains
• each switch has its own collision domain
• each hub has its own collision domain

Cabling

Straight-through Cable

Crossover Cable

How to choose the right cable

Crossover cable

The endpoints transmit on the same pin pair

Straight-through cable

The endpoints transmit on different pin pairs

Transmits on Pins 1,2	Transmits on Pins 3,6
PC NICs	Hubs
Routers	Switches
WLANs ( Ethernet interface)

Frame

Type field

Used to describe the data type inside the frame.

FCS

Frame Check Sequence