It is true that 10Base-T and 100Base-T unshielded twisted-pair cabling uses two pairs, both full duplex and half duplex.
It is true that It's not the cabling that distinguishes half-duplex and full-duplex. It's the logical topology, hardware, and configuration. But, if you want to run 100Base-T and full-duplex depend you must take care on the cable4s length and quality. It functions better if you have CAT-5 or CAT-5E cable. ----- Original Message ----- From: "Priscilla Oppenheimer" To: Sent: Friday, January 11, 2002 9:59 AM Subject: Re: full-duplex Ethernet cable? [7:31643] > At 11:56 AM 1/11/02, mlh wrote: > >how many pairs of two-twisted cable are used for full-duplex Ethernet ? what > >is the > >difference between full- and half- duplex cable? > > 10Base-T and 100Base-T unshielded twisted-pair cabling uses two pairs, for > both full duplex and half duplex. There's a transmit pair and a receive > pair. A station's transmit pair gets crossed over at the hub or switch to > mean receive at the hub or switch. The hub or switch's transmit pair > becomes receive at the station. > > It's not the cabling that distinguishes half-duplex and full-duplex. It's > the logical topology, hardware, and configuration. > > With half-duplex, if a station receives bits on its receive pair while > transmitting bits on its transmit pair, this is considered a collision. The > station must stop transmitting, back off, and retransmit. A half-duplex > network is shared. Every device on the hub (or coax cable) shares the > bandwidth and must obey the rules of Carrier Sense Multiple Access, > Collision Detect. Listen before sending. Listen while sending to see if > another station started sending at the same time and back off if that's the > case. > > Full duplex works on a point-to-point link between a station and a switch. > Bandwidth is not shared. In this case, receiving while you are sending it > perfectly legitimate. > > So, to upgrade a network from half-duplex to full-duplex doesn't require > new cabling, but it does require a new logical topology and possibly new > hardware: switches and Network Interface Cards (NICs) that support full > duplex. It also requires that the administrator configure everything for > full duplex (or use auto-negotiation which is risky because it's buggy.) > > Hope that helps. > > Priscilla > > > > >Thank you in advance. > > > > > > > >Regrads, > > > >mlh > ________________________ > > Priscilla Oppenheimer > http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=31676&t=31643 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
