A Content Delivery Network (CDN) distributes content across multiple servers located in different regions. This improves page load times by serving content from the closest server to the user. Using a CDN can significantly reduce page load times, increase revenue, retain more customers, and make content delivery more scalable and secure. Key factors in selecting a CDN provider include the provider's coverage of user locations and capabilities in meeting specific business needs.

1. Content Delivery Network - What You Really Need To Know

2. What is a Content Delivery Network CDN?
Using a Content Delivery Network (CDN) hosting instead of a
standard hosting means that you will load some of the traffic to cloud
based servers in data centers strategically located in different
regions of the world. The servers from a data center closer to the
end user will always be triggered, so the content reaches him faster.
CDNs are basically surrogate web servers distributed across
different data centers in different geographical regions to deliver
content to end-users, based on proximity of this user. They help
global availability of a website, address the latency problems and
gain size, i.e. reduce bandwidth.

3. What Kind of Problems CDN Solve?
Implementing a CDN affects everything, from your internal architecture to the cost of
your IT staff, performance management and more. True power of a content delivery
network is yet to be revealed in future decades, as it soars by 20% each year, but so
far, the major advantages of using one are:
• significantly reduced page load time of your website
• increased revenue by 1% for every 100 ms of improvement to your page load time
• retaining more customers (they are more satisfied)
• more manageable traffic
• maximum availability of your product
• more secure network
• no geographical barriers
• easy delivery of video, audio rich content

4. • build more interactive website at no cost of losing visitors due to latencies
• reaching mobile customers with ease
• branching out to new markets, regions
• easy management of traffic peaks
• more scalability to your business, you can grow it as much as you want to
• less or now downtimes
• setting your own criteria to enable the best possible performance for your website

5. • build more interactive website at no cost of losing visitors due to latencies
• reaching mobile customers with ease
• branching out to new markets, regions
• easy management of traffic peaks
• more scalability to your business, you can grow it as much as you want to
• less or now downtimes
• setting your own criteria to enable the best possible performance for your website
How can I implement CDN?
More than 90% of business owners now realize the benefits of using
the cloud, the reliability of the cloud and cloud investments keep them
on top of the market and safe against competitors.
Implementing a CDN to the cloud gives them even more market
opportunities, helps them scale their business as much as they need
to, and pushes them to keep up with technological revolutions.
There are no general rules to how to implement CDNs since each type
of CDN has its own configuration process. What is important is that
YSlow recognizes the CDN and for blogs you may even use plug-ins.

6. How much does a CDN cost?
The usage of Content Delivery Networks (CDNs) is rapidly growing in the era of
mobile and app-based internet. The effort to simplify navigation and improve user
experience is taken both by vendors and network operators.
The speed of a website affects everything, from infrastructure to cost of an e-
commerce. With CDNs, the data is served to the end-user from the surrogate server
located nearest to him.
A CDN replicates content from the origin server to cache servers, scattered over the
globe. Renting such service from a CDN provider has proved to be much simpler and
more cost effective than maintaining an on-premise server of your own.
Also, the content that the vendors provide is seeking to be highly interactive, and the
varying round-trip of the content/data needs to be optimized, the latency minimized.

7. Of course, the value measured will depend on the type of the service provided, on
whether you are a vendor/content owner, or a CDN service provider. For the content
owners, basically two questions need to be answered to find where the value of their
CDN implementation lies:
• how does it improve overall retail service delivery?
• how does it support their efforts to win/retain customers?
There are many different stakeholders in the CDN market, like content providers,
content makers, data centre providers, Internet Service providers (ISPs), Internet
access providers, Internet backbone providers, CDN providers, advertisers, and so
forth.
As the market dynamics continue to evolve, so will evolve the profiles, the merging
trends, and price strategies of different stakeholders.

8. What is POP?
POPs (also, points of presence, edge caches) are distributed servers where
static resources are stashed across a region or worldwide, thereby bringing
resources closer to users and reducing round trip time.

9. Is there anything else I can do to speed up my
website?
The options to make your website faster, split in two major categories:
• speeding up your browser side technologies (browser caching, minifying
page elements, minimizing redirects)
• speeding up by using some of the acceleration technologies (Content
Delivery Networks, dynamic CDN, media streaming)

10. Browser-side optimization
Use the optimal formatting for images: JPEG’s are for photographs, GIF’s are for low
color images/flat color images, and PNG’s are for everything else. Also, try and adjust
the image size yourself, i.e. set the width and height (width=’60px’ height=’30px’). Use
web tools for image optimization (such as Riot, ImageOptim). Don’t store everything
locally, try using services like Flickr.
Minify the code for CSS and JavaScript. Again, there are some tools available such as
Code Minifier, Minify, JSCompress, CSSCompressor… Put CSS in separate .css files,
not embedded in each page. Put Java Script files in .js files, or if you need to include
them in HTML, put them at the bottom of the HTML page.

11. Browser-side optimization #2
Reduce the number of components of your page. Make a simple design. This will
immediately reduce the number of HTTP requests to download all the graphics, video
and JavaScript files from your website. Also, avoid Flash elements, or use as little as
possible. Try to host as much elements as possible on other websites.
Minimize redirects. Each redirect creates an additional HTTP request and adds RTT
(round-trip-time) latency. Use redirects only when absolutely necessary. The more
redirection you have, the slower the end user will get to the desired page.

12. Server-side optimization
Reduce DNS Lookups. It takes some milliseconds for DNS (Domain Name System) to
resolve an IP address for a given hostname or domain name. The browser cannot do
anything until the process is fully completed. Ideally, you should use no more than 4
hostnames. This will also allow for a higher degree of parallel downloads.
Set up a GZIP compression on your web server. It saves bandwidth and solves
problems with older browsers. The compressing options vary depending on the
server.

13. Server-side optimization #2
Employ media streaming methods. Real-time protocols will read compressed files to
deliver data as it arrives. And dismiss the data once it has been streamed. The option
to stream media will allow faster views, and compression/decompression methods will
dispose of all the unnecessary data that would otherwise clog your connection.
Don’t forget to run a website speed test first. In this way, you will know more precisely
which components need to be targeted first. There are many tools that can detect
the root cause of your website being not fast enough, such as YSlow, Pingdom,
WebPageTest, Cuzillion, Wireshark, HTTP Archive, PageSpeed and so on.

14. Is CDN useful for every site?
The first rule of e-commerce says that if the customer cannot find your
product/service, he cannot buy it. The number of web shoppers in US alone in 2011
was said to be 178,5 million and is to reach 200 million by 2015 (source: eMarketer)
which will equal 90% of all internet users in US.
Now, to consider the patience of your customers. 1 out of 4 customers is sure to
abandon a webpage that takes more than 4 seconds to load.
So, yes, improving performance is absolutely a must for every website except if the
content is hosted locally and their users are local, in that case CDN doesn’t make that
big of a difference.

15. What Can I Expect as a Result of Using a CDN?
Faster websites result in better user experience, better search engine rankings
and more conversions. 1 out of 4 visitors won’t wait for the page to load for more
than 4 seconds. The ideal is to find balance between neat performance and
indulging the end users’ desire for interactivity, delivering script intensive
content.
CDNs help with major performance problems on the server-side, mainly latency,
availability and bandwidth.

16. How Should I Select My CDN Vendor?
As CDN performance primarily depends on geographical location and the proximity of
POPs to end-users, you should locate your users first. Also, you should know who
your regular user is, define the type of content you are delivering, your business
model and what specific requirements you need in order to become more successful.
Knowledge of your specific needs is crucial as performance fluctuates among CDN
providers. With this information you make a request for proposal and go through the
feedback the CDN or service provider gives you. It is important that you get an idea
of:
• how will network performance be measured
• what chances there are for outages and how will you be compensated
• if the provider will charge overages
• what is indeed supported in terms of delivery

17. What If I Don’t See Any Results?
Providers of Content Delivery Networks (CDNs) vary in service. Some will perform better in China, some
in US, some in Australia. Some will include one feature, but not the other. And you’ll want to be on the
right cloud at the right time.
CDNs are known to provide a more secure network, reduced loading time of your page, manageable
traffic, maximum availability, and so on. An irreplaceable tool that will improve the entire technological
infrastructure that backs up your business. Whether you are in e-commerce business, or your website is
supposed to deliver various audio, video rich content.
Using multiple CDNs is smarter than using one CDN because:
• CDN providers perform differently in different geographical regions
• Not all CDN providers are reliable as others
• Not all CDN providers include same features and strategies as others
• You don’t need to switch CDN providers as this process becomes automated

18. Shouldn’t I just optimize my website?
Statistics for your uptime, response time, website performance. Plus,historical
records of all downtimes and errors and performing speed tests (e.g. with Pingdom)
will help you decide whether you need to only improve your CSS files asset, do
simple optimizing tricks, or use Content Delivery Network (CDN) hosting which uses
servers located at different data centers to deliver content from the server that is
closest to the end user.
Bear in mind that 250 milliseconds will make a difference between you and your
competitor, nowadays.

19. Does CDN guarantee 100% availability?
CDNs improve overall global availability of a website but the performance
depends on the geographical location of a server and of a vendor, as well as the
number of vendors that you are hiring. Having more than one is a surest way to
avoid downtimes.

20. Conclusion
With global CDN market changing and bringing ever
more performance technologies and solutions, it is
rather complex to describe each and every potential
use case. It depends on your overall business goals,
strategies and competitive landscape on which
performance technologies will you use. Use the
comments to ask additional questions on which we’ll
try to answer in future blog posts.
Visit www.globaldots.com for further info.

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inquiries.
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