User Manual Part 2

Table Of Contents
Glossary of Terms
776 Check Point Safe@Office User Guide
M
MAC Address
The MAC (Media Access Control)
address is a computer's unique hardware
number. When connected to the Internet
from your computer, a mapping relates
your IP address to your computer's
physical (MAC) address on the LAN.
Mbps
Megabits per second. Measurement unit
for the rate of data transmission.
MTU
The Maximum Transmission Unit
(MTU) is a parameter that determines
the largest datagram than can be
transmitted by an IP interface (without
it needing to be broken down into
smaller units). The MTU should be
larger than the largest datagram you
wish to transmit un-fragmented. Note:
This only prevents fragmentation
locally. Some other link in the path may
have a smaller MTU - the datagram will
be fragmented at that point. Typical
values are 1500 bytes for an Ethernet
interface or 1452 for a PPP interface.
N
NAT
Network Address Translation (NAT) is
the translation or mapping of an IP
address to a different IP address. NAT
can be used to map several internal IP
addresses to a single IP address, thereby
sharing a single IP address assigned by
the ISP among several PCs.
Check Point FireWall-1's Stateful
Inspection Network Address Translation
(NAT) implementation supports
hundreds of pre-defined applications,
services, and protocols, more than any
other firewall vendor.
NetBIOS
NetBIOS is the networking protocol
used by DOS and Windows machines.
P
Packet
A packet is the basic unit of data that
flows from one source on the Internet to
another destination on the Internet.
When any file (e-mail message, HTML
file, GIF file etc.) is sent from one place
to another on the Internet, the file is
divided into "chunks" of an efficient
size for routing. Each of these packets is
separately numbered and includes the
Internet address of the destination. The
individual packets for a given file may
travel different routes through the
Internet. When they have all arrived,
they are reassembled into the original
file at the receiving end.
PPPoE
PPPoE (Point-to-Point Protocol over
Ethernet) enables connecting multiple
computer users on an Ethernet local area
network to a remote site or ISP, through
common customer premises equipment
(e.g. modem).