User's Manual

50
Glossary
This chapter presents a more detailed description of the Broadband Home Router’s
configuration parameters.
DHCP (Dynamic Host
Configuration Protocol)
When operates as a DHCP server, the
Broadband Home Router assign IP
addresses to the client PCs on the
LAN. The client PCs “leases” these
Private IP addresses for a
user-defined amount of time. After
the lease time expires, the private IP
address is made available for
assigning to other network devices.
The DHCP IP address can be a
single, fixed public IP address, an ISP
assigned public IP address, or a
private IP address.
If you enable DHCP server on a
private IP address, a public IP
address will have to be assigned to
the NAT IP address, and NAT has to
be enabled so that the DHCP IP
address can be translated into a public
IP address. By this, the client PCs are
able to access the Internet.
LAN (Local Area Network) &
WAN (Wide Area Network)
A LAN is a computer network
limited to the immediate area, usually
the same building or floor of a
building. A WAN, on the other hand,
is an outside connection to another
network or the Internet.
The Ethernet side of the Broadband
Home Router is called the LAN port.
It is a twisted-pair Ethernet 10Base-T
interface. A hub can be connected to
the LAN port. More than one
computers, such as server or printer,
can be connected through this hub to
the Broadband Home Router and
composes a LAN.
The WAN port of the Broadband
Home Router composes the WAN
interface, which supports PPP or
RFC 1483 connecting to another
remote DSL device of cable modem.
Authentication and WEP
Encryption
The absence of a physical connection
between nodes makes the wireless
links vulnerable to eavesdropping and
information theft. To provide a
certain level of security , the IEEE
8002.11 standard has defined two
types of authentication methods, open
system and shared key. With open
system authentication a wireless PC
can join any network and receive any
messages that are not encrypted. With
shared key authentication, only those
PCs that possess the correct
authentication key can join the
network. By default IEEE 802.11
wireless devices operate in an Open
system network.
Private IP Address
Private IP addresses are also LAN IP
addresses, but are considered
“illegal” IP addresses to the Internet.
They are private to an enterprise
while still permitting full network
layer connectivity between all hosts
inside an enterprise as well as all
public hosts of different enterprises.
The Broadband Home Router uses
private IP addresses by assigning
them to the LAN that cannot be
directly accessed by the Internet or
remote server. To access the Internet,
private network should have an agent
to translate the private IP address to
public IP address.
RIP (Routing Information
Protocol)
RIP is a routing protocol that uses the
distance-vector routing algorithms to
calculate least-ho
p
s routes to a
UDP (User Data gram Protocol)
UDP is a connectionless transport
service that dispenses with the
reliability services provided by TCP.
UDP
g
ives a
pp
lications a direct