Redirection for Multiple TCP Port Destined Traffic
 
WCCP v2 enables more TCP ports to have traffic redirected to the cache engine. Previously, web-cached information could be redirected only if it was destined for TCP port 80. Many applications require packets intended for other ports to be redirected, for example, proxy-web cache handling, FTP caching, FTP proxy handling, web caching for ports other than 80, and Real Audio, video, and telephony applications.
 
Packets that the cache engines do not service are tunneled back to the same router from where they were received. Once a router has received a formerly redirected packet, it knows not to redirect it again.
 
The criteria set for determining whether to redirect the traffic is as follows:
 
•IP protocol
 
•ports
 
•priority
 
•distribution scheme
 
•default handling
 
Note that service information has been added to the protocol to indicate which service the WCCP messages refer to. This information is used to help validate that service group members are all using or providing the same service.