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Glossary
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NMP
Network Management Processor: A Catalyst 5000 switch processor
module used to control and monitor the switch.
node address
Used to identify a specific device in an internetwork. Can be
a hardware address, which is burned into the network interface card, or a
logical network address, which an administrator or server assigns to the node.
Non-Broadcast Multi-Access (NBMA)
A type of network that does not,
by default, allow LAN broadcasts to be transmitted on the network. An
example of an NBMA is Frame Relay.
nondesignated port
The Spanning Tree Protocol tells a port on a Layer 2
switch to stop transmitting and creating a network loop. Only designated
ports can send frames.
non-stub area
In OSPF, a resource-consuming area carrying a default
route, intra-area routes, inter-area routes, static routes, and external routes.
Non-stub areas are the only areas that can have virtual links configured
across them and exclusively contain an anonymous system boundary router
(ASBR). Compare with: stub area. See also: ASBR and OSPF.
NRZ
Nonreturn to Zero: One of several encoding schemes for transmitting
digital data. NRZ signals sustain constant levels of voltage with no signal
shifting (no return to zero-voltage level) during a bit interval. If there is a
series of bits with the same value (1 or 0), there will be no state change. The
signal is not self-clocking. See also: NRZI.
NRZI
Nonreturn to Zero Inverted: One of several encoding schemes for
transmitting digital data. A transition in voltage level (either from high to
low or vice versa) at the beginning of a bit interval is interpreted as a value
of 1; the absence of a transition is interpreted as a 0. Thus, the voltage
assigned to each value is continually inverted. NRZI signals are not self-
clocking. See also: NRZ.
NT1
network termination 1: An ISDN designation to devices that under-
stand ISDN standards.
NT2
network termination 2: An ISDN designation to devices that do not
understand ISDN standards. To use a NT2, you must use a terminal
adapter (TA).
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