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D-Link Unified Access Point Administrator’s Guide
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two special host numbers:
• The Network Address consists of a host number
that is all zeroes (for example,
10.90.2.0
).
• The Broadcast Address consists of a host number
that is all ones (for example,
10.90.2.255
).
There are a finite number of IP addresses that can
exist. Therefore, a local area network typically uses
one of the
IANA -designated address ranges for use in
private networks. These address ranges are:
10.0.0.0
to
10.255.255.255
172.16.0.0
to
172.31.255.255
192.168.0.0
to
192.168.255.255
A Dynamic IP Address is an IP address that is
automatically assigned to a host by a DHCP server or
similar mechanism. It is called dynamic because you
may be assigned a different IP address each time you
establish a connection.
A Static IP Address is an IP address that is hard-
wired for a specific host. A static address is usually
required for any host that is running a server, for
example, a Web server.
IPSec
IP Security (IPSec) is a set of protocols to support the
secure exchange of packets at the
IP layer. It uses
shared public keys. There are two encryption modes:
Transport and Tunnel.
• Transport mode encrypts only the data portion
(payload) of each packet, but leaves the headers
untouched.
• The more secure Tunnel mode encrypts both the
header and the payload.
ISP
An Internet Service Provider (ISP) is a company that
provides access to the Internet to individuals and
companies. It may provide related services such as
virtual hosting, network consulting, Web design, etc.
J
Jitter
Jitter is the difference between the latency (or delay)
in packet transmission from one node to another
across a network. If packets are not transmitted at a
consistent rate (including
Latency ), QoS for some
types of data can be affected. For example,
inconsistent transmission rates can cause distortion in
VoIP and streaming media.
QoS is designed to
reduce jitter along with other factors that can impact
network performance.
L
Latency
Latency, also known as delay, is the amount of time it
takes to transmit a
Packet from sender to receiver.
Latency can occur when data is transmitted from the
access point to a client and vice versa. It can also
occur when data is transmitted from access point to
the Internet and vice versa. Latency is caused by
fixed network factors such as the time it takes to
encode and decode a packet, and also by variable
network factors such as a busy or overloaded
network.
QoS features are designed to minimize
latency for high priority network traffic.
LAN
A Local Area Network (LAN) is a communications
network covering a limited area, for example, the
computers in your home that you want to network
together or a couple of floors in a building. A LAN
connects multiple computers and other network
devices such as storage and printers.
Ethernet is the
most common technology implementing a LAN.
Wireless Ethernet ( 802.11 ) is another very popular
LAN technology (also see WLAN ).
LDAP
The Lightweight Directory Access Protocol (LDAP)
is a protocol for accessing on-line directory services.
It is used to provide an authentication mechanism. It
is based on the X.500 standard, but less complex.