GLOSSARY 161

 

with periods (full-stops), and is made up of a network section, an

 

optional subnet section and a host section.

LAN

Local Area Network. A network of client machines (such as PCs,

 

printers, servers) and network devices (hubs and switches) that cover a

 

relatively small geographic area (usually not larger than a floor or

 

building). LANs are characterized by high transmission speeds over

 

short distances (up to 1000 m).

LAN port

An auto-negotiating 10BASE-T/100BASE-TX RJ-45 port which is used to

 

connect the Webcache to the network in either Proxy or Transparent

 

deployment environments.

latency

The delay between a web request being issued from the Web browser

 

on a client machine and the information arriving back at the browser.

line speed

See baud.

MRTG

Multi Router Traffic Grapher. A graphing tool provided with the

 

Webcache that enables you to monitor the Webcache’s performance.

NTP

Network Time Protocol. This protocol is used to synchronize the time of

 

client machines and servers with other well-known, highly accurate

 

servers or reference time sources (such as a radio, satellite receiver or

 

modem). It maintains a consistent Coordinated Universal Time (UTC)

 

within your network which is far more accurate than the internal

 

system clocks of client machines.

origin server

The web server that contains the original copy of the requested

 

information.

PAC

Proxy Auto Configuration. PAC files allow you to create configuration

 

rules that determine how Web browsers operate when the Webcache is

 

being deployed in a Proxy cache.

PING

Packet Internet or Inter-Network Gropher. This feature allows you to

 

send out a PING request to test whether devices on an IP network are

 

accessible and functioning correctly.

protocol

A set of rules for communication between devices on a network. The

 

rules dictate format, timing, sequencing and error control.