Specifications

Altitude 3500 Series Access Point Product Reference Guide
29
For detailed information on manually setting the access point’s system time, see “Configuring Network
Time Protocol (NTP)” on page 98.
Dynamic DNS
The access point supports the Dynamic DNS service. Dynamic DNS (or DynDNS) is a feature offered by
www.dyndns.com which allows the mapping of domain names to dynamically assigned IP addresses.
When the dynamically assigned IP address of a client changes, the new IP address is sent to the
DynDNS service and traffic for the specified domain(s) is routed to the new IP address. For information
on configuring the Dynamic DNS feature, see “Configuring Dynamic DNS” on page 132.
Auto Negotiation
Auto negotiation enables the access point to automatically exchange information (over either its LAN or
WAN port) about data transmission speed and duplex capabilities. Auto negotiation is helpful when
using the access point in an environment where different devices are connected and disconnected on a
regular basis. For information on configuring the auto negotiation feature, see “Configuring the LAN
Interface” on page 113 or “Configuring WAN Settings” on page 125
Theory of Operations
To understand Altitude 35xx access point management and performance alternatives, users need
familiarity with its functionality and configuration options. The access point includes features for
different interface connections and network management.
The access point uses electromagnetic waves to transmit and receive electric signals without wires.
Users communicate with the network by establishing radio links between mobile units (MUs) and access
points.
The access point uses DSSS (direct sequence spread spectrum) to transmit digital data from one device to
another. A radio signal begins with a carrier signal that provides the base or center frequency. The
digital data signal is encoded onto the carriers using a DSSS chipping algorithm. The radio signal
propagates into the air as electromagnetic waves. A receiving antenna (on the MU) in the path of the
waves absorbs the waves as electrical signals. The receiving MU interprets (demodulates) the signal by
reapplying the direct sequence chipping code. This demodulation results in the original digital data.
The access point uses its environment (the air and certain objects) as the transmission medium.The
Altitude 35xx access point can either transmit in the 2.4 to 2.5-GHz frequency range (802.11b/g radio) or
the 5 GHz frequency range (802.11a radio), the actual range is country-dependent. Extreme Networks
devices, like other Ethernet devices, have unique, hardware encoded Media Access Control (MAC) or
IEEE addresses. MAC addresses determine the device sending or receiving data. A MAC address is a
48-bit number written as six hexadecimal bytes separated by colons. For example: 00:A0:F8:24:9A:C8
Also see the following sections:
● Wireless Coverage on page 30
● MAC Layer Bridging on page 30
● Content Filtering on page 23
● DHCP Support on page 26
● Media Types on page 31