Chapter 11 Avaya P330 Layer 2 Features
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.
