3Com SuperStack 3 3812 Implementation Manual page 102

102 G
LOSSARY
LLC Logical Link Control. A sublayer of the IEEE data link layer that is
located above the MAC sublayer. The LLC sublayer is responsible for
MAC sublayer addressing, flow control, error control, and framing.
latency The delay between the time a device receives a packet and the time the
packet is forwarded out of the destination port.
line speed See baud.
loop An event that occurs when two network devices are connected by
more than one path, thereby causing packets to repeatedly cycle
around the network and not reach their destination.
MAC Media Access Control. A protocol specified by the IEEE for determining
which devices have access to a network at any one time.
MAC address Media Access Control address; also called hardware or physical address.
A layer 2 address associated with a particular network device. Most
devices that connect to a LAN have a MAC address assigned to them
as they are used to identify other devices in a network. MAC addresses
are 6 bytes long.
main port The port in a resilient link that carries data traffic in normal operating
conditions.
MDI Medium Dependent Interface. An Ethernet port connection where the
transmitter of one device is connected to the receiver of another
device.
MDI-X Medium Dependent Interface Cross-over. An Ethernet port connection
where the internal transmit and receive lines are crossed.
MIB Management Information Base. A collection of information about the
management characteristics and parameters of a networking device.
MIBs are used by the Simple Network Management Protocol (SNMP) to
gather information about the devices on a network. The Switch
contains its own internal MIB.
multicast A packet sent to a specific group of endstations on a network.
multicast filtering A system that allows a network device to only forward multicast traffic
to an endstation if it has registered that it would like to receive that
traffic.