Intel EXPRESS 550T - Manuel (Page 121)

111
Introduction
Purpose Too many users (on a LAN) requesting the same information from
the Internet can cause congestion on the WAN link. A single stand-
alone Express 550T Routing Switch can redirect TCP packets from
popular sites and make a local copy of them in one of up to four Web
Server Caches. Users requesting the same information are then sup-
plied with a copy from the local server cache. This reduces WAN bot-
tle-necks and uses the available bandwidth more efficiently.
TCP packets are redirected using their TCP port numbers. For exam-
ple, HTTP packets (TCP port number 80) are commonly redirected,
while e-mail packets (TCP port number 25) would not normally be
redirected to a server cache. The TCP port numbers and their respec-
tive destinations are defined from within Intel Device View.
Configuration TCP packet redirection is only possible through the front ports of this
switch (including ports in installed 4TX and 2FX modules). The ports
are set to function in one of three ways: “Client” ports connect work-
6
Redirect TCP Packets
500.book Page 111 Thursday, September 2, 1999 1:50 PM