Specifications

April 16, 2009 Page 1 of 14
Configuring Transparent Web Cache Balancing
(TWCB)
Thisdocumentprovidesthe followinginformationaboutconfiguringTransparentWebCache
BalancingontheEnt erasysMatrix
®
N‐Seriesplatform.
What is User Transparent Web Cache Balancing (TWCB)?
TransparentWebCacheBalancing(TWCB)providesforthestoringoffrequentlyaccessedweb
objectsonacacheoflocalservers.EachHTTPrequestistransparentlyredirectedbytheN‐Series
routertoaconfiguredcacheserver.Whenauserfirstaccessesawebobject,thatobjectisstoredon
acache
server.Eachsubsequentrequestfortheobjectusesthiscachedobject,avoidingtheneedto
accessthehostwebsite.
Why Would I Use TWCB in My Network?
Formostnetworks,webservicesaretheprimaryconsumerofnetworkbandwidth.Webcaching
reducesnetworktrafficandaidesinoptimizingbandwidthusagebylocalizingwebtraffic
patterns,allowingcontentrequeststobefulfilledlocally.Webcachingallowsend‐userstoaccess
webobjectsstoredonlocalcache‐serverswitha
muchfasterresponsetimethanaccessingthe
sameobjectsoveraninternetconnectionorthroughadefaultgateway.Thiscanalsoresultin
substantialcostsavingsbyreducingtheinternetbandwidthusage.
TWCBaddsthreeimportantelementstostandardwebcaching:transparency,loadbalancing,and
scalability:
•Instandardwebcaching,
networkusersmustsettheirbrowserstocachewebtraffic.Because
webcachingishighlysensitivetouserpreference,userssometimesbalkatthisrequirement,
andtheinabilitytocontroluserbehaviorcanbeaproblemforthenetworkadministrator. 
TWCBissaidtobetransparenttotheuserbecauseweb
trafficisautomaticallyrerouted,and
theabilitytoconfigurecachingisremovedfromtheuserandresidesinsteadinthehandsof
thenetworkadministrator.WithTWCBtheusercannotby‐passwebcachingoncesetupby
thenetworkadministrator.Ontheotherhand,thenetworkadministratorcan
addusersfor
For information about... Refer to page...
What is User Transparent Web Cache Balancing (TWCB)? 1
Why Would I Use TWCB in My Network? 1
How Can I Implement TWCB? 2
TWCB Overview 2
Configuring TWCB 7
TWCB Configuration Example 10