Chapter 11 Avaya P330 Layer 2 Features
74 Avaya P332G-ML User’s Guide
Ethernet
Ethernet is one of the most widely implemented LAN standards. It uses the Carrier
Sense Multiple Access with Collision Detection (CSMA/CD) access method to
handle simultaneous demands. CSMA/CD is a multi-user network allocation
procedure in which every station can receive the transmissions of every other
station. Each station waits for the network to be idle before transmitting and each
station can detect collisions by other stations.
The first version of Ethernet supported data transfer rates of 10 Mbps, and is
therefore known as 10BASE-T.
Fast Ethernet
Fast Ethernet is a newer version of Ethernet, supporting data transfer rates of 100
Mbps. Fast Ethernet is sufficiently similar to Ethernet to support the use of most
existing Ethernet applications and network management tools. Fast Ethernet is also
known as 100BASE-T (over copper) or 100BASE-FX (over fiber).
Fast Ethernet is standardized as IEEE 802.3u.
Gigabit Ethernet
Gigabit Ethernet supports data rates of 1 Gbps. It is also known as 1000BASE-T
(over copper) or 1000BASE-FX (over fiber).
Gigabit Ethernet is standardized as IEEE 802.3z.
Configuring Ethernet Parameters
Auto-Negotiation
Auto-Negotiation is a protocol that runs between two stations, two switches or a
station and a switch. When enabled, Auto-Negotiation negotiates port speed and
duplex mode by detecting the highest common denominator port connection for the
endstations. For example, if one workstation supports both 10 Mbps and 100 Mbps
speed ports, while the other workstation only supports 10 Mbps, then
Auto-Negotiation sets the port speed to 10 Mbps.
For Gigabit ports, Auto-Negotiation determines the Flow Control configuration of
the port.
Full-Duplex/Half-Duplex
Devices that support Full-Duplex can transmit and receive data simultaneously, as
opposed to half-duplex transmission where each device can only communicate in
turn.
Full-Duplex provides higher throughput than half-duplex.