Intel 1520 用户手册

Appendix A Caching Solutions and Performance

A WCCP 2.0-enabled router can send all port 80 (HTTP) traffic to the Intel 
NetStructure Cache Appliance, as shown in Figure 4. After the WCCP router 
sends port 80 traffic, the ARM readdresses port 80 to the appliance proxy port (by 
default, port 8080). Then the appliance processes the request as usual, retrieving 
the requested document from the cache if it is a hit and sending the response back 
to the client. Along the way, the ARM readdresses the proxy port in the response 
header to port 80 (undoing the readdressing it did on the way to the appliance). 
The user then sees the response exactly as if it were sent directly from the origin 
server. In addition to port 80 (HTTP) traffic, WCCP 2.0 supports more protocols 
including NNTP (port 119 traffic).

WCCP provides the following routing benefits:

✔ The WCCP-enabled router and the appliance exchange heartbeat messages, 

letting each other know they are running. The WCCP router automatically 
reroutes port 80 and port 119 traffic if the appliance goes down.

✔ If several appliances receive traffic from a WCCP router, WCCP balances the 

load among them. The group of appliances is called a WCCP cache farm.