User guide

I-6 VMS User Guide
N
NAT Network Address Translation – An Internet standard that enables a LAN to use
one set of IP addresses for internal (private) traffic and a second set of addresses
for external (public) traffic.
NIC Network Interface Controller – The network interface for a PC/workstation that
provides Ethernet connectivity. Depending on the computer, the NIC can either
be built into the motherboard, or be an expansion card. Some computers (e.g.,
servers) have multiple NICs, each identified by a unique IP address.
NMS Network Management System
NOC Network Operation Center – Has access to any earth station installed using the
VIPERSAT Management System (VMS). A NOC can remotely interrogate,
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.
OPEX Operating Expenditure
OSPF Open Shortest Path First – A common routing algorithm.
P
PLDM Path Loss Data Multicast – A message that is sent every sixty seconds and
contains information on messages received or lost.
PSTN Public Switched Telephone Network – The world’s public circuit-switched
telephone network, digital and analog, and includes mobile as well as land-line
voice and data communications.