Extreme Networks Summit WM User Manual page 309

Term
DHCP
Directory Agent (DA)
Diversity antenna and
receiver
DNS
DSSS
DTIM
Summit WM User Guide, Software Version 5.3
Explanation
Dynamic Host Configuration Protocol. A protocol for assigning dynamic IP
addresses to devices on a network. With dynamic addressing, a device can
have a different IP address every time it connects to the network. In some
systems, the device's IP address can even change while it is still connected.
DHCP also supports a mix of static and dynamic IP addresses.
DHCP consists of two components: a protocol for delivering host-specific
configuration parameters from a DHCP server to a host and a mechanism
for allocation of network addresses to hosts. (IETF RFC1531.)
Option 78 specifies the location of one or more SLP Directory Agents.
Option 79 specifies the list of scopes that a SLP Agent is configured to
use.(RFC2610 - DHCP Options for Service Location Protocol)
A method of organizing and locating the resources (such as printers, disk
drives, databases, e-mail directories, and schedulers) in a network. Using
SLP, networking applications can discover the existence, location and
configuration of networked devices.
With Service Location Protocol, client applications are 'User Agents' and
services are advertised by 'Service Agents'. The User Agent issues a
multicast 'Service Request' (SrvRqst) on behalf of the client application,
specifying the services required. The User Agent will receive a Service
Reply (SrvRply) specifying the location of all services in the network which
satisfy the request.
For larger networks, a third entity, called a 'Directory Agent', receives
registrations from all available Service Agents. A User Agent sends a
unicast request for services to a Directory Agent (if there is one) rather than
to a Service Agent.
(SLP version 2, RFC2608, updating RFC2165)
The AP has two antennae. Receive diversity refers to the ability of the AP
to provide better service to a device by receiving from the user on which
ever of the two antennae is receiving the cleanest signal. Transmit diversity
refers to the ability of the AP to use its two antenna to transmit on a
specific antenna only, or on a alternate antennae. The antennae are called
diversity antennae because of this capability of the pair.
Domain Name Server
Direct-Sequence Spread Spectrum. A transmission technology used in Local
Area Wireless Network (LAWN) transmissions where a data signal at the
sending station is combined with a higher data rate bit sequence, or
chipping code, that divides the user data according to a spreading ratio.
The chipping code is a redundant bit pattern for each bit that is
transmitted, which increases the signal's resistance to interference. If one or
more bits in the pattern are damaged during transmission, the original data
can be recovered due to the redundancy of the transmission. (Compare
FHSS)
DTIM delivery traffic indication message (in 802.11 standard)
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