Nomadix Access Gateway, Руководство пользователя

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Misconfigured User
A Nomadix, Inc. term used to describe users who have IP address configurations that are different from the current
network. For example, if the current network is 123.45.67.89 but the user’s IP address is 10.10.10.15, then this user is
considered to be “misconfigured.”
NAT
(Network Address Translation) An Internet standard that enables a Local Area Network (LAN) to use one set of IP
addresses for internal traffic and a second set of IP addresses for external traffic. A NAT box located where the LAN
meets the Internet performs all the necessary IP address translations. NAT provides a type of firewall by hiding its
internal IP addresses. Additionally, NAT enables companies to use more internal IP addresses (because the addresses
are only used internally and there’s no possibility of conflicting with IP addresses used by other companies). NAT also
allows companies to combine multiple ISDN connections into a single Internet connection. See also,
ISDN
.
Node
An addressable point on a network. A node can connect a computer system, a terminal, or various peripheral devices to
the network. Each node on a network has a distinct name. On the Internet, a node is a host computer with a unique
domain name and IP address. See also,
Domain Name and IP Address .
NTP
(Network Time Protocol) An Internet standard protocol (built on top of TCP/IP) that assures accurate synchronization
(to the millisecond) of computer clock times in a network of computers. Based on
UTC
, NTP synchronizes client
workstation clocks to the U.S. Naval Observatory master clocks. Running as a continuous background client program
on a computer, NTP sends periodic time requests to servers, obtaining server time stamps and using them to adjust the
client's clock.
OFDM
(Orthogonal Frequency Division Multiplexing) An
FDM
modulation technique for transmitting large amounts of
digital data over a radio wave. OFDM works by splitting the radio signal into multiple smaller sub-signals that are then
transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount of crosstalk in signal
transmissions. 802.11a WLAN technology uses OFDM.
OSPF
(Open Shortest Path First) This routing protocol was developed for IP networks based on the shortest path first or link-
state algorithm. Routers use link-state algorithms to send routing information to all nodes on a network by calculating
the shortest path to each node based on a topography of the Internet constructed by each node. Routers send that
portion of the routing table (keeping track of routes to particular network destinations) that describes the state of its
own links, and it also sends the complete routing structure (topography). The advantage of shortest path first
algorithms is that they result in smaller more frequent updates everywhere. They converge quickly, thus preventing
such problems as routing loops and count-to-infinity (when routers continuously increment the hop count to a
particular network). This makes for a stable network. OSPF (version 2) is defined in RFC 1583 and is rapidly replacing
RIP on the Internet as the preferred routing protocol. See also,
RFC and Router .
Packet
How data is distributed over the Internet. A packet contains the source and destination addresses, as well as the data.
An ethernet packet is normally 1,518 bytes. In IP networks, packets are often called datagrams. See also,
Forwarding
Rate , Packet Switching Network , pps , and Throughput .