Nortel 15000 Terminology page 92

NTP
See network time protocol (NTP) (page
NTS
See Network Time Synchronization (NTS) System (page
numbering-plan indicator (NPI)
The part of a given data network address that defines the numbering plan to
which it belongs. Examples of numbering plans defined by ITU-T are X.121
and E.164.
OAM
See operations, administration, and maintenance (OAM) (page
OC-3
Optical carrier level 3. In SONET networks, OC-3 is the optical form of the first
SONET multiplexing level when it is transmitted through an optical fiber. The
155.52 Mbit/s OC-3 signal is made up of three multiplexed OC-1 basic
channels.
OC-12
An optical carrier signal in the SONET optical format that is 12 times the OC-
1 rate.
OC-48
A high-speed optical carrier signal in the SONET optical format providing a
line rate of 2.488 Gbits/s, ATM services, and traffic management.
OC-N
Optical Carrier level N. The optical signal that results from an optical
conversion of an STS-N signal.
off-network call
A call destined to another network. An off-network call crosses one or more
gateways.
on-network call
A call that is routed internally through the SCR and DCR systems to a
destination within the network.
open shortest path first (OSPF)
An IP routing model defined in RFC 1583, whereby the shortest route to a
destination is calculated from a database of link states.
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List of terms
Nortel Multiservice Switch 7400/15000/20000
Terminology
NN10600-005 7.2S1 Standard
PCR7.2 and up March 2006
88).
89).
Nortel Confidential
93).