BROCADE IP PRIMER

424C424C424C424C424C424CConsolePwrActive10/100/1000EthernetFastIron SX800LinkAct1 LinkAct2424C424C424C424C424C424CPwrActiveConsole10/100/1000EthernetLinkAct1 LinkAct2What is Transparent Cache Switching?ClientGET /www/index.htmlGET /image.gifServerIronGET /www/index.htmlGET /image.gifweb 1web 2Group 1GET /cgi-bin/app.cgiGET /cgi-bin/app.cgiimage 2image 1Group 2App 1 App 2Group 3There is much more flexibility with URL switching than we can cover in thisbook. For more information, see Brocade's web site(http://www.brocade.com/).What is Transparent Cache Switching?Before we answer this question, let's look at its parts. A cache server is aserver that processes web requests more efficiently than by directing everyrequest to the Internet. For example, if you have 50 LAN users all requestingthe same web page, you could forward all 50 requests out to the Internet. Or,you could forward one request to the Internet, store the resulting page on alocal cache server, and redirect the other 49 requests to the local cacheserver.The act of redirecting the other 49 requests is considered Cache Switching.You are making a decision as to whether you will forward a request to the Internet(as the item is not yet on the cache server), or redirect the request to thelocal cache server. This is often the secondary function of a proxy server inmany corporate LANs. The proxy server serves as both a proxy server and acache server. This requires clients to configure their workstations so that allweb requests are funneled through the proxy server.But what if you don't want to use a proxy server, and you don't want to changeall of your user's workstation configurations? This is where the transparentpiece of it comes in to play. In Transparent Cache Switching (TCS), theServerIron intercepts the web request transparently and decides whether therequest should be forwarded to the Internet, or to the cache server. This entireprocess is transparent to the client.Brocade IP Primer 365