willardmo...
This article by Telephony Online, from Sep 15, 1997, discusses
the value of the Cisco Cache Engines following their introduction
a week earlier:
"Cisco Systems last week introduced the carrier-class Cache
Engine, designed to store up to 800,000 Web pages that
otherwise would make repeated trips across the Internet."
"The goal is to save bandwidth and improve download time by
delivering data from the Cache Engine that end users request
frequently, such as photos from Princess Diana's funeral or
from the Mars mission. The process reduces the number of
times that service providers use their wide area network
connections and helps them reduce costs."
"The Cache Engine requires no client configuration, making
it transparent to the user. It communicates with a Cisco
router, which redirects Web requests to the Cache Engine
using the Web Cache Control Protocol, a new feature of
Cisco's IOS software. Service providers then have no need
to reconfigure their clients' browsers."
Since the engines intercept Web-based traffic, content control
can be installed so that service providers can provide filtered
accounts. Such filters for screening out pornography and gambling
can be used by schools and libraries.
"The effective caching performance scales with the number of
incremental Cache Engines. The service provider needs only
to add more engines to scale up. You don't have to add new
protocols, invest in asynchronous transfer mode, change your
infrastructure or, if you're a Cisco user, change the routers
themselves".
http://telephonyonline.com/ar/telecom_content_pit_stops/
Another page which illustrates the functionality of the caching
engine is this one from Oracle.com:
"Cache engines used within an e-business network provide the
function named as Reverse-Proxy caching. Reverse-Proxy caching
allows the cache engines to offload connection requests from
the web servers for static content. Content requests received
from Internet clients are proxied by the cache engines. If the
cache engines do not possess a copy of the content, they will
retrieve it from the web servers, answer the client request,
and store the information for future requests. The caching
function helps scale the performance of the web servers by
reducing the number of connections they must answer for static
content."
"The protocol that enables the cache engine interaction with
the network is called the Web Cache Communication Protocol
(WCCP). It allows the routers or layer-3 switches to
communicate with the cache engines in a highly available way.
Using WCCP v2, cache engines can be arranged in a cluster
formation and homed to multiple routers. This arrangement
creates a design in which no single point of failure exists."
http://www.oracle.com/ecostructure/blueprint_res/implement_network_cisco_cashe_engine_configuration.htm
So the primary advantage offered by the cache engines is that
of taking the brunt of repetitive requests away from the primary
servers by storing frequently requested pages. This leaves the
servers breathing space which allow for the rapid delivery of
specialized, unusual or dynamic content. Assuming your servers
periodically show signs of stress from the repeated delivery
of static content, you would benefit from the use of a cache
engine. I was unable to locate any 'cons' to the use of these
engines, since they provide a degree of redundancy which
decreases the likelihood of delivery failure, and provide
an increase in delivery speed.
Cisco stands out in the search results as the primary provider of
cache engines, though Squid is "a full-featured Web proxy cache
designed to run on Unix systems, and is free, open-source software":
http://www.squid-cache.org/
Squid is supported by various hardware as listed here:
http://www.squid-cache.org/products.html
One of these, e.g., is the Tsunami, from SwellTech:
"The Tsunami web caching appliance offers security, reliability,
and flexibility by leveraging the power of Open Source Software.
Combining a tightly integrated hardware platform with an easy
to use GUI and proven software components the Tsunami is an
affordable solution."
"The Tsunami caching appliance is an easy to use and powerful
caching solution for ISPs, small business, enterprise and
education environments. The Tsunami enhances the user
experience, conserves network resources and improves security"
http://www.swelltech.com/
Cisco, of course, is the best known solution, and their 500
series have their home on the following page. Note that the
page states:
"This product has reached end-of-sale or end-of-life status;
it cannot be ordered and may no longer be supported."
http://www.cisco.com/en/US/products/hw/contnetw/ps546/
...and...
A comprehensive overview of the CE570, 550 and 505 are
on the following page, as well as a notation that
"The Cache Engine 570, 550, and 505 have been replaced by the
Content Engine 500 Series."
http://cisco.com/univercd/cc/td/doc/pcat/ce500.htm#xtocid2
The Content Engine 500 Series are found here:
http://www.cisco.com/en/US/products/hw/contnetw/ps761/index.html
A comprehensive overview of the Cisco 507, 560, 590, and
7320 Content Engines are on this page:
http://cisco.com/univercd/cc/td/doc/pcat/ce____g1.htm
...and the CE 510, 565, 7305, and 7325 Content Engines are
explored and contrasted on this page:
http://cisco.com/univercd/cc/td/doc/pcat/ce507560.htm
Exploring the technical specifications on the above pages will
help you determine the model which best suits your needs.
A potentially valuable advantage of the 7300 series Cisco
Content Engines is the embedded Websense Enterprise v4.4.1
software:
"Used by more than 18,100 organizations worldwide, and
preferred by the Fortune500, Websense Enterprise is the world’s
leading employee Internet management (EIM) software solution.
Websense Enterprise v4.4.1 embedded on Cisco Content
Engines allows you to transparently analyze, manage and report
on traffic flowing from your internal networks to the Internet.
Using pass-through technology, it is tightly integrated with the
Cisco Content Engine, giving you the most accurate, reliable
and scalable Internet filtering solution available. Websense
Enterprise is also easy to install and administer."
http://www.websense.com/products/about/datasheets/v5/cce-on.pdf
In short, it allows complete control over what internet sites
can be accessed by employees, and when. A full explanation of
of the configurability is given in this page from the WebSense
website. This is only available on "7300 series Content Engine
appliances":
http://www.websense.com/products/integrations/v5/integration.cfm?id=203
Please do not rate this answer until you are satisfied that
the answer cannot be improved upon by means of a dialog
established through the "Request for Clarification" process.
sublime1-ga
Searches done, via Google:
"cache engines"
://www.google.com/search?q=%22cache+engines%22
"content engines"
://www.google.com/search?q=%22content+engines%22
...and searches through the Cisco website. |
