Glossary
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MTU
maximum transmission unit: The largest packet size, measured in
bytes, that an interface can handle.
multicast
Broadly, any communication between a single sender and mul-
tiple receivers. Unlike broadcast messages, which are sent to all addresses
on a network, multicast messages are sent to a defined subset of the network
addresses; this subset has a group multicast address, which is specified
in the packet's destination address field. See also: broadcast and directed
broadcast.
multicast address
A single address that points to more than one device
on the network by specifying a special non-existent MAC address specified
in that particular multicast protocol. Identical to group address. See also:
multicast.
multicast send VCC
A two-directional point-to-point virtual control con-
nection (VCC) arranged by an LEC to a BUS, it is one of the three types of
informational links specified by phase 1 LANE. See also: control distribute
VCC and control direct VCC.
multilayer switch
A highly specialized, high-speed, hardware-based type
of LAN router, the device filters and forwards packets based on their layer-
2 MAC addresses and layer-3 network addresses. It's possible that even
layer-4 can be read. Sometimes called a layer-3 switch. See also: LAN switch.
multilink
Used to combine multiple Async or ISDN links to provide com-
bined bandwidth.
multiplexing
The process of converting several logical signals into a single
physical signal for transmission across one physical channel. Contrast with:
demultiplexing.
NAK
negative acknowledgment: A response sent from a receiver, telling the
sender that the information was not received or contained errors. Compare
with: acknowledgment.
NAT
network address translation: An algorithm instrumental in mini-
mizing the requirement for globally unique IP addresses, permitting an orga-
nization whose addresses are not all globally unique to connect to the
Internet nevertheless, by translating those addresses into globally routable
address space.
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