CDNs + FEO + OCA = Web Performance Optimization (WPO)
Today’s Internet offers a wealth of dynamic content —
customized ads, streaming and on-demand videos,
product recommendations, news articles and more —
that enhances the user’s online experience. Website
visitors expect great website design, but they also
want fast load times. A slow website will negatively
impact the customer experience, search engine
results and, ultimately, sales or readership.
Content delivery networks (CDNs), front-end optimization
(FEO) and origin content acceleration (OCA) are new
technologies for optimizing performance. Separately, these
tools offer a partial fix but can’t provide the complete answer
for the increasingly complex dynamic content being
used on websites.
Think of these tools as three legs on the Web performance
optimization (WPO) stool, which, when combined,
can deliver faster performance — especially for
dynamic interactive advertising and Web video content.
AN OVERVIEW OF WPO
WPO evolved as webmasters looked for ways to address
the growing demand for high-quality, downloadable and
streaming rich media. But WPO technology really took off
with the advent of Web 2.0, which changed the nature of
Web 2.0 technologies encourage user interactivity and
personalization, changing the nature of Web traffic. The
formerly synchronous transfer of static content from
server to browser has yielded to traffic composed of an increasing
bi-directional mix of static and dynamic content,
served up independently to customize user Web experiences
and allow website operators to tailor ads and content
to specific user interests.
As consumers and companies come to depend more
and more on the Web to deliver information and services,
the use of WPO techniques to reduce page-load times is
becoming essential. While consumer patience thresholds
for load times will vary by industry, online retailers can
be sure that any significant delay will be detrimental to
the amount or quality of page views, revenues and search
THE DIFFERENT APPROACHES
Content Delivery Networks
CDNs have become very popular among website owners
who have media-rich sites with Web objects (text,
graphics, URLs and scripts), downloadable objects
(media files, software and documents), applications (ecommerce,
portals), on-demand and live-streaming
media, and social networks.
A CDN is a system of servers located close to endusers,
which contain cached copies of original data or
content. When users request content, the request is routed
to the server closest to them, shortening the distance the
content has to travel and improving download speed by
Once a service for sophisticated websites, the CDN
market has become commoditized with the explosion of
small business e-commerce sites and blogs — making
affordable CDN services widely available for small websites
and blogs as well as large ones. Any website owner
can easily sign up for a low-cost CDN by doing some
comparison research on costs and options and then signing
Most services integrate easily with websites, are up and
running quickly and provide customer service to help with
any problems. CDNs can be purchased on a monthly basis
or through a pay-as-you-go model.
While CDNs help to address part of the slow website
problem by reducing network latency, not all content
can be stored in a CDN. Front-end optimization software
helps speed up the transport of origin content over
the network by automatically streamlining Web page
HTML code and the number of page resources required
to download a given page, as well as making the browser
process the page faster.
A popular FEO tool called mod_pagespeed
(http://wsm.co/KGGzqK) has been made available by
Google. Mod_pagespeed is an open-source tool for Apache
servers that can significantly reduce page-load times. Other
FEO site optimizers are available from various vendors, as
appliances that can be installed in the data center of a large
website or as a service via the cloud for smaller sites.
Origin Content Acceleration
CDNs and FEO help speed up websites by delivering
cached content faster and speeding up the user’s browser
process, but neither of these methods can solve network
latency problems inherent in dynamic content coming
from origin servers.
The main performance problem involved in serving
content from origin is caused by inefficiency in the primary
Internet transport protocol (TCP, for transmission
control protocol), which was not designed for Web 2.0
content. TCP focuses on data transport reliability and redundancy,
not speed, low latency and the media-rich data
present in Web 2.0.
Because of this, these protocols break down over long
distances, and in congested environments requiring repeated
retransmission of packets, result in low effective
throughput — especially impacting data delivered from
origin servers. Moreover, these protocols perform exponentially
worse as distance and congestion increase, leading
to even greater end-user dissatisfaction.
Origin content acceleration solves the issue of distancerelated
network latency by accelerating origin-served content
from the server to the end-user using algorithms to fix
inefficient network protocols in order to reduce the transport
latency between the origin server and the user. OCA
accelerates all content — dynamic and static — all the way
to the end-user’s computer or mobile device.
In fact, the greater the distance, the greater the benefit
that OCA provides, resulting in fast-performing websites
both in the U.S. and in other countries such as
China, India and South America, where congestion is
high and where the transport distance can be very long.
OCA is available as a combination of software modules
and appliances that can be installed on the server side,
with no browser plug-in or software clients needed at
the receiving end.
HOW IT WORKS
On today’s websites that have both dynamic, origin-served
content and static files that can be cached, it is often the
origin-served content that must come first before calls are
made for images, style sheets and other cached elements.
The figure shown illustrates the typical path of Web data
to a user’s computer, with cacheable content being served
from regional CDN servers and non-cacheable content
being delivered from an origin server.
In many cases, the origin-served content is the gating
factor on webpage performance because the whole page
must wait on the origin-served content. Webpage load
time, then, is more critical than ever in order to ensure a
satisfactory end-user experience.
A complete approach that leverages all three of the
WPO approaches mentioned in this article should be considered
to achieve the goal of delivering a webpage in less
than two seconds, regardless of distance from the enduser.
Current solutions that include CDN (moving the
content closer to the end-user) and FEO (content optimization)
offer benefits that, when integrated with OCA
(origin content acceleration), provide the best possible
advantages for fast websites.
About the Author: Jerry Hall is vice president of marketing at FastSoft, a company
whose products aim to increase website and Web application
performance and speed the distribution of video and
other digital content across the Internet.