Quick Reference Guide

Reference Guide for the Model FR314, FR318 and FV318 Cable/DSL Firewall and VPN Routers
Glossary 3
local area network
LAN. A communications network serving users within a limited area, such as
one floor of a building. A LAN typically connects multiple personal
computers and shared network devices such as storage and printers. Although
many technologies exist to implement a LAN, Ethernet is the most common
for connecting personal computers.
MAC address
Media Access Control address. A unique 48-bit hardware address assigned to
every Ethernet node. Usually written in the form 01:23:45:67:89:ab.
MSB
See Most Significant Bit or Most Significant Byte.
MRU
See Maximum Receive Unit.
MTU
See Maximum Transmit Unit.
Maximum Receive
Unit
The size in bytes of the largest packet that can be received.
Maximum Transmit
Unit
The largest size packet, including all headers and data, that can be transmitted
over a given network. Ethernet networks typically use an MTU of 1500 bytes.
Most Significant Bit or
Most Significant Byte
The portion of a number, address, or field that is farthest left when written as a
single number in conventional hexadecimal ordinary notation. The part of the
number having the most value.
NAT
See Network Address Translation.
netmask
A number that explains which part of an IP address comprises the network
address and which part is the host address on that network. It can be
expressed in dotted-decimal notation or as a number appended to the IP
address. For example, a 28-bit mask starting from the MSB can be shown as
255.255.255.192 or as /28 appended to the IP address.
Network Address
Translation
A technique by which several hosts share a single IP address for access to the
Internet.
packet
A block of information sent over a network. A packet typically contains a
source and destination network address, some protocol and length
information, a block of data, and a checksum.
PPP
See Point-to-Point Protocol.
PPP over Ethernet
PPPoE. PPP over Ethernet is a protocol for connecting remote hosts to the
Internet over an always-on connection by simulating a dial-up connection.