E-6 Vipersat CDD-564L User’s Guide
N
NAT Network Address Translation - An Internet standard that enables a local-area
network (LAN) to use one set of IP addresses for internal (private) traffic and a
second set of addresses for external (public) traffic.
NOC Network Operation Center (NOC) has access to any earth station installed using
the VIPERSAT Network Control System (VNCS). An NOC can remotely inter-
rogate, control, and log network activities.
O
ODU Outdoor Unit – In a VSAT system the RF components (transceiver) are usually
installed outdoors on the antenna structure itself and are thus referred to as an
ODU.
OSPF Open Shortest Path First - A common routing algorithm.
P
PLDM Path Loss Data Multicast message is sent every sixty seconds and

contains information on messages received or lost.

POP3 Post Office Protocol 3 - A protocol for exchanging e-mail messages between
host computers. See also SMTP.
PMUX Port Multiplexing - Each port of the SDMS is individually configured from the
NMS port (hub) to port (remote) multiplexing.
PSTN Public Switched Telephone Network - Refers to the international telephone
system based on copper wires carrying analog voice data.
Q
QPSK Quaternary Phase Shift Keying – A modulation technique in which the carrier
is phase shifted +/- 90 or +/-180 degrees. See also BPSK