OPX
Issue 1.0 May 2003
419
NID
Network Inward Dialing
NM
Network management
NN
National number
node
A switching or control point for a network. Nodes are either tandem (they receive
signals and pass them on) or terminal (they originate or terminate a transmission
path).
Nonfacility-associated
signaling (NFAS)
A method that allows multiple T1 and/or E1 facilities to share a single D-channel to
form an ISDN-PRI. If D-channel backup is not used, one facility is configured with a
D-channel, and the other facilities that share the D-channel are configured without
D-channels. If D-channel backup is used, two facilities are configured to have D-
channels (one D-channel on each facility), and the other facilities that share the D-
channels are configured without D-channels.
NPA
Numbering-plan area
NPE
Network processing element
NQC
Number of queued calls
NSE
Night-service extension
NSU
Network sharing unit
null modem cable
Special wiring of an RS-232-C cable such that a computer can talk to another
computer (or to a printer) without a modem.
NXX
Public-network office code
OA
Operator assisted
occurrence
See
appearance
on page 389.
OCM
Outbound Call Management
offered load
The traffic that would be generated by all the requests for service occurring within a
monitored interval, usually one hour.
ONS
On-premises station
OPS
Off-premises station
OPX
Off-premises extension