148 GLOSSARY
LC Line Card. A card in the VCN AC chassis; the card provides an Ethernet
port and an LMI port.
LED Light Emitting Diode. A semi-conductor device that converts electrical
energy into light, used, for example, for the activity lights on the VCN
AC and VCN AP units and appears in green or orange.
LMA Local Management Access.
MAC Media Access Control. A protocol that defines the way workstations
gain access to transmission media, most widely used in reference to
LANs. For IEEE LANs, the MAC layer is the lower sublayer of the data
link layer protocol.
MAC address Media Access Control address; also called hardware or physical address.
A data link layer address associated with a particular LAN device. MAC
addresses are 6 bytes long.
Mbaud Megabaud
Mbps Megabits per second.
MiniDIN A connector which connects the VCN AC to the Local Management
Interface.
NA Not Applicable. Wherever this appears, it means that the specified
condition is irrelevant for the case mentioned.
NAT Network Address Translation. The process of converting between IP
addresses used within an Intranet or other private network and Internet
IP addresses. This approach makes it possible to use a large number of
addresses within the local Intranet without depleting the limited
number of available numeric Internet IP addresses.
NAU Network Access Unit. In this case it is the unit installed in a room which
enables both voice and high speed data services simultaneously on the
existing telephone line. Another name for the VCN AP.
NCU Network Concentration Unit. Another name for the VCN AC.
NIC Network Interface Card. An expansion card or other device used to
connect a computer to a local area network.
NSP Network Service Provider