Parent Caching - 3Com SUPERSTACK 3 WEBCACHE 3000 User Manual

Parent Caching

Layer 4 redirection device. All Web traffic arriving from client machines to
the LAN port of the Webcache is directed into the caching software. All
non-Web traffic is automatically sent back out onto the network via the
WAN port. Cache misses are automatically redirected from the LAN port
to the WAN port.
For further information, see
page 118.
Advantages
You do not have to add new devices to your network. Therefore it is
I
easy to try out the Webcache in your network.
No configuration of the Web browser on each client machine is
I
needed because all network traffic goes through the Webcache.
Disadvantages
The Webcache is a single point of failure; if it fails, the entire network
I
becomes inaccessible.
All incoming and outgoing network traffic is handled by the software
I
built into the Webcache. The peak packet rate that can be sustained is
therefore lower than using a Layer 4 device, resulting in reduced
performance.
Parent Caching allows you to explicitly configure a hierarchy of
Webcaches within your network. Web requests from client machines that
are not fulfilled by a child Webcache (cache misses) can be routed to
parent Webcaches instead of the origin Web server. If a parent Webcache
has the requested content, it serves it back to the child Webcache, which
in turn caches and serves it back to the client machines.
For further information, see
You can configure a child Webcache to use parent caching regardless of
which deployment mode it is currently operating in. The child Webcache
uses the TCP port number that you configure for the parent Webcache to
send its requests.
Any compliant HTTP proxy cache can be used as a parent Webcache. The
parent Webcache does not have to be a 3Com SuperStack 3 Webcache.
"Configuring Inline Cache Mode"
"Configuring Parent Caching"
Parent Caching 53
on
on page 119.