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Appendix D Wireless LANs
NBG-419N User’s Guide
256
4
The AP and wireless clients use the TKIP or AES encryption process, the PMK and information
exchanged in a handshake to create temporal encryption keys. They use these keys to encrypt data
exchanged between them.
Figure 165
WPA(2)-PSK Authentication
Security Parameters Summary
Refer to this table to see what other security parameters you should configure for each
authentication method or key management protocol type. MAC address filters are not dependent on
how you configure these security features.
Antenna Overview
An antenna couples RF signals onto air. A transmitter within a wireless device sends an RF signal to
the antenna, which propagates the signal through the air. The antenna also operates in reverse by
capturing RF signals from the air.
Table 95
Wireless Security Relational Matrix
AUTHENTICATION
METHOD/ KEY
MANAGEMENT PROTOCOL
ENCRYPTIO
N METHOD
ENTER
MANUAL KEY
IEEE 802.1X
Open
None
No
Disable
Enable without Dynamic WEP Key
Open
WEP
No
Enable with Dynamic WEP Key
Yes
Enable without Dynamic WEP Key
Yes
Disable
Shared
WEP
No
Enable with Dynamic WEP Key
Yes
Enable without Dynamic WEP Key
Yes
Disable
WPA
TKIP/AES
No
Enable
WPA-PSK
TKIP/AES
Yes
Disable
WPA2
TKIP/AES
No
Enable
WPA2-PSK
TKIP/AES
Yes
Disable
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Appendix D Wireless LANs
NBG-419N User’s Guide
257
Positioning the antennas properly increases the range and coverage area of a wireless LAN.
Antenna Characteristics
Frequency
An antenna in the frequency of 2.4GHz or 5GHz is needed to communicate efficiently in a wireless
LAN
Radiation Pattern
A radiation pattern is a diagram that allows you to visualize the shape of the antenna’s coverage
area.
Antenna Gain
Antenna gain, measured in dB (decibel), is the increase in coverage within the RF beam width.
Higher antenna gain improves the range of the signal for better communications.
For an indoor site, each 1 dB increase in antenna gain results in a range increase of approximately
2.5%. For an unobstructed outdoor site, each 1dB increase in gain results in a range increase of
approximately 5%. Actual results may vary depending on the network environment.
Antenna gain is sometimes specified in dBi, which is how much the antenna increases the signal
power compared to using an isotropic antenna. An isotropic antenna is a theoretical perfect antenna
that sends out radio signals equally well in all directions. dBi represents the true gain that the
antenna provides.
Types of Antennas for WLAN
There are two types of antennas used for wireless LAN applications.
Omni-directional antennas send the RF signal out in all directions on a horizontal plane. The
coverage area is torus-shaped (like a donut) which makes these antennas ideal for a room
environment. With a wide coverage area, it is possible to make circular overlapping coverage
areas with multiple access points.
Directional antennas concentrate the RF signal in a beam, like a flashlight does with the light
from its bulb. The angle of the beam determines the width of the coverage pattern. Angles
typically range from 20 degrees (very directional) to 120 degrees (less directional). Directional
antennas are ideal for hallways and outdoor point-to-point applications.
Positioning Antennas
In general, antennas should be mounted as high as practically possible and free of obstructions. In
point-to–point application, position both antennas at the same height and in a direct line of sight to
each other to attain the best performance.
For omni-directional antennas mounted on a table, desk, and so on, point the antenna up. For
omni-directional antennas mounted on a wall or ceiling, point the antenna down. For a single AP
application, place omni-directional antennas as close to the center of the coverage area as possible.
Page 258 / 292
Appendix D Wireless LANs
NBG-419N User’s Guide
258
For directional antennas, point the antenna in the direction of the desired coverage area.
Page 259 / 292
NBG-419N User’s Guide
259
A
PPENDIX
E
Common Services
The following table lists some commonly-used services and their associated protocols and port
numbers. For a comprehensive list of port numbers, ICMP type/code numbers and services, visit
the IANA (Internet Assigned Number Authority) web site.
Name
: This is a short, descriptive name for the service. You can use this one or create a
different one, if you like.
Protocol
: This is the type of IP protocol used by the service. If this is
TCP/UDP
, then the service
uses the same port number with TCP and UDP. If this is
USER-DEFINED
, the
Port(s
) is the IP
protocol number, not the port number.
Port(s)
: This value depends on the
Protocol
. Please refer to RFC 1700 for further information
about port numbers.
If the
Protocol
is
TCP
,
UDP
, or
TCP/UDP
, this is the IP port number.
If the
Protocol
is
USER
, this is the IP protocol number.
Description
: This is a brief explanation of the applications that use this service or the situations
in which this service is used.
Table 96
Commonly Used Services
NAME
PROTOCOL
PORT(S)
DESCRIPTION
AH
(IPSEC_TUNNEL)
User-Defined
51
The IPSEC AH (Authentication Header)
tunneling protocol uses this service.
AIM/New-ICQ
TCP
5190
AOL’s Internet Messenger service. It is
also used as a listening port by ICQ.
AUTH
TCP
113
Authentication protocol used by some
servers.
BGP
TCP
179
Border Gateway Protocol.
BOOTP_CLIENT
UDP
68
DHCP Client.
BOOTP_SERVER
UDP
67
DHCP Server.
CU-SEEME
TCP
UDP
7648
24032
A popular videoconferencing solution from
White Pines Software.
DNS
TCP/UDP
53
Domain Name Server, a service that
matches web names (for example
www.zyxel.com
) to IP numbers.
ESP
(IPSEC_TUNNEL)
User-Defined
50
The IPSEC ESP (Encapsulation Security
Protocol) tunneling protocol uses this
service.
FINGER
TCP
79
Finger is a UNIX or Internet related
command that can be used to find out if a
user is logged on.
FTP
TCP
TCP
20
21
File Transfer Program, a program to enable
fast transfer of files, including large files
that may not be possible by e-mail.
H.323
TCP
1720
NetMeeting uses this protocol.
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Appendix E Common Services
NBG-419N User’s Guide
260
HTTP
TCP
80
Hyper Text Transfer Protocol - a client/
server protocol for the world wide web.
HTTPS
TCP
443
HTTPS is a secured http session often used
in e-commerce.
ICMP
User-Defined
1
Internet Control Message Protocol is often
used for diagnostic or routing purposes.
ICQ
UDP
4000
This is a popular Internet chat program.
IGMP (MULTICAST)
User-Defined
2
Internet Group Management Protocol is
used when sending packets to a specific
group of hosts.
IKE
UDP
500
The Internet Key Exchange algorithm is
used for key distribution and
management.
IRC
TCP/UDP
6667
This is another popular Internet chat
program.
MSN Messenger
TCP
1863
Microsoft Networks’ messenger service
uses this protocol.
NEW-ICQ
TCP
5190
An Internet chat program.
NEWS
TCP
144
A protocol for news groups.
NFS
UDP
2049
Network File System - NFS is a client/
server distributed file service that provides
transparent file sharing for network
environments.
NNTP
TCP
119
Network News Transport Protocol is the
delivery mechanism for the USENET
newsgroup service.
PING
User-Defined
1
Packet INternet Groper is a protocol that
sends out ICMP echo requests to test
whether or not a remote host is reachable.
POP3
TCP
110
Post Office Protocol version 3 lets a client
computer get e-mail from a POP3 server
through a temporary connection (TCP/IP
or other).
PPTP
TCP
1723
Point-to-Point Tunneling Protocol enables
secure transfer of data over public
networks. This is the control channel.
PPTP_TUNNEL
(GRE)
User-Defined
47
PPTP (Point-to-Point Tunneling Protocol)
enables secure transfer of data over public
networks. This is the data channel.
RCMD
TCP
512
Remote Command Service.
REAL_AUDIO
TCP
7070
A streaming audio service that enables
real time sound over the web.
REXEC
TCP
514
Remote Execution Daemon.
RLOGIN
TCP
513
Remote Login.
RTELNET
TCP
107
Remote Telnet.
RTSP
TCP/UDP
554
The Real Time Streaming (media control)
Protocol (RTSP) is a remote control for
multimedia on the Internet.
SFTP
TCP
115
Simple File Transfer Protocol.
Table 96
Commonly Used Services (continued)
NAME
PROTOCOL
PORT(S)
DESCRIPTION

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