The traditional shared LAN operates in half-duplex mode, like with
hubs, and is susceptible to transmission collisions across the wire.
Full-duplex Ethernet signi?¬?cantly improves network performance without the expense of
installing new media. Full-duplex transmission between stations is achieved by using pointto-
point Ethernet, Fast Ethernet, and Gigabit Ethernet connections. This arrangement is
collision-free. Frames sent by the two connected end nodes cannot collide because the end
nodes use two separate circuits in the unshielded twisted-pair (UTP) cable. Each fullduplex
connection uses only one port.
Full-duplex port connections are point-to-point links between switches or end nodes, but
not between shared hubs. Nodes that are directly attached to a dedicated switch port with
network interface cards (NIC) that support full-duplex should be connected to switch ports
that are con?¬?gured to operate in full-duplex mode. Most Ethernet, Fast Ethernet, and
Gigabit Ethernet NICs sold today offer full-duplex capability. In full-duplex mode, the
collision detect circuit is disabled.
Nodes that are attached to hubs that share their connection to a switch port must operate in
half-duplex mode because the end stations must be able to detect collisions.
Pages:
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273