3Com 3C17203 - SuperStack 3 Switch 4400, Implementation Manual

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96 C
HAPTER
9: U
SING
W
EBCACHE
S
UPPORT
Webcache Support
Example
Figure 22 shows a Switch 4400 in a network with a Webcache connected
to the network and enabled. The Switch identifies all HTTP traffic flowing
through it and redirects all HTTP traffic to the Webcache.
Figure 22 Example of a network with Webcache Support enabled
In Figure 22 the flow of HTTP traffic between a PC browsing the World
Wide Web, the Webcache and the WAN connection is as follows:
1 A PC sends a request for a web page, in the form of HTTP traffic.
2 The Switch receives the request from the PC, it detects that the traffic is
HTTP, and redirects it to the Webcache instead of the WAN.
3 The Webcache receives the request. If it has the required web page
cached it will send it directly back to the requesting PC. If it does not have
the page cached, it will return the request to the Switch (on its cache
port) and the Switch will forward the request on to the WAN.
4 The requested page comes back from the WAN addressed to the
Webcache.
5 The Webcache caches the web page for future use and also sends it to
the requesting PC.