Internet Performance for Dummies

Internet
Performance
by Lawrence Miller, CISSP
Dyn Special Edition

Internet Performance For Dummies®
, Dyn Special Edition
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Table of Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About This Book......................................................................... 1
Foolish Assumptions.................................................................. 1
Icons Used in This Book............................................................. 2
Beyond the Book......................................................................... 2
Where to Go from Here.............................................................. 3
Chapter 1: What Internet Performance Is
and Why It Matters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Recognizing Business Challenges in a Connected World...... 5
Defining Internet Performance.................................................. 6
History of the World (Wide Web), Part I.................................. 7
ARPANET........................................................................... 8
The World Wide Web....................................................... 8
The dot.com boom – and bust........................................ 9
Amazon, Facebook, iPhone, and the Internet
of Things........................................................................ 9
Chapter 2: Internet 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
ISP Levels................................................................................... 11
ISP Peering and Transit Arrangements.................................. 13
DNS............................................................................................. 16
CDNs........................................................................................... 17
Chapter 3: Website, Application, and
Service Dependencies. . . . . . . . . . . . . . . . . . . . . . . . . . 21
How Websites Work................................................................. 21
Managing Service‐Level Agreements (SLAs)......................... 22
Chapter 4: Internet Performance in the
Eyes of Your Customers. . . . . . . . . . . . . . . . . . . . . . . . . 27
Always Reachable..................................................................... 28
Always Fast................................................................................ 28
Always Secure........................................................................... 29

Internet Performance For Dummies, Dyn Special Edition iv
Chapter 5: Internet Performance
in the Eyes of Your Business . . . . . . . . . . . . . . . . . . . . 33
Common Cloud Adoption Fears.............................................. 33
Revenue‐Driven Decisions....................................................... 35
Efficient Spend on Internet Resources................................... 36
Protect Your Brand................................................................... 37
Addressing Internet Performance Challenges....................... 38
Chapter 6: Ten Key Internet Performance
Takeaways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Implement Managed DNS......................................................... 41
Provide Redundant Access to Your Cloud Services............. 42
Measure Cloud Performance to Key Markets........................ 42
Explore Problem Mitigation Before It Happens.................... 42
Catch Problems Early and Update DNS................................. 43
Improve the End‐User Experience.......................................... 43
Enforce SLAs.............................................................................. 43
Maximize Asset Utilization...................................................... 44
Increase Revenues.................................................................... 44
Focus on Core Competencies.................................................. 44

These materials are © 2015 John Wiley Sons, Inc. Any dissemination, distribution, or unauthorized use is strictly prohibited.
Introduction
The structure and performance of the Internet remains a
huge blind spot for most enterprises, even those critically
dependent on it for business operations. Customer‐facing
websites and applications must be reliable, fast, and secure
in order for businesses to attract new customers and retain
existing ones. Otherwise, today’s online global consumers will
take their business elsewhere.
Connected businesses need real‐time and historical insight
into the structure and performance of the Internet to rap-
idly adapt their online infrastructure and make the changes
necessary to increase revenue, decrease costs, and optimize
Internet availability, reachability, reliability, speed, and
security.
About This Book
This book provides an overview of Internet Performance —
what it means to your customers and to your business, and
what you need to do to ensure your public websites and appli-
cations always perform at the level your global customers and
your business require.
Foolish Assumptions
I assume you have at least a basic working knowledge of the
Internet and its role in our global economy. If you believe the
Internet is just a passing fad and you have your assistant print
your emails, you may want to have your assistant read this
book for you.
Next, I assume that you’re a business or technical executive
or midlevel manager in your organization, and you need to
better understand how Internet Performance impacts cus-
tomer satisfaction and the success of your business.

Internet Performance For Dummies, Dyn Special Edition 2
Lastly, I assume that you believe the Internet is best‐effort and
can’t actually be optimized for your business. After you read
this guide, you will understand that there are many things
you can do to make the Internet work for you. If you want the
Internet to be your competitive edge, then this is the book
for you!
Icons Used in This Book
Throughout this book, I occasionally use special icons to
call attention to important information. Here’s what you can
expect:
This icon points out information that may well be worth com-
mitting to your nonvolatile memory, your gray matter, or your
noggin — along with anniversaries and birthdays!
You won’t find a map of the human genome here, but if you
seek to attain the seventh level of NERD‐vana, perk up! This
icon explains the jargon beneath the jargon!
Thank you for reading, hope you enjoy the book, please take
care of your writers! Seriously, this icon points out helpful
suggestions and useful nuggets of information.
These helpful alerts offer practical advice to help you avoid
making potentially costly mistakes.
Beyond the Book
Although this book is chock full of information, there’s only
so much I can cover in 48 short pages! So, if you find yourself
at the end of this book, thinking “Gosh, this was an amazing
book, where can I learn more about Internet Performance?”
simply go to www.dyn.com.

Introduction 3
Where to Go from Here
If you don’t know where you’re going, any chapter will get you
there — but Chapter 1 might be a good place to start!
However, if you see a particular topic that piques your inter-
est, feel free to jump ahead to that chapter. Each chapter is
individually wrapped (but not packaged for individual sale)
and written to stand on its own, so you can start reading
anywhere and skip around to your heart’s content! Read this
book in any order that suits you (though I don’t recommend
upside down or backwards).

WhatInternetPerformance
IsandWhyItMatters
In This Chapter
▶▶ Identifying why Internet Performance matters
▶▶ Outlining the characteristics of Internet Performance
▶▶ Tracing the Internet from its roots to the present
In this chapter, I describe some of the modern business
challenges that companies must address in the global,
technology‐driven economy. You’ll also learn exactly what
Internet Performance is — and isn’t. Finally, I end the chapter
with a brief history of the Internet.
Recognizing Business Challenges
in a Connected World
Today’s fast‐paced and ever‐changing global economy is
largely driven by technology. As a result, the following trends
have emerged:
✓✓ The Internet makes every business a global business.
Online shopping has no borders. According to Dyn’s
Global Consumer Online Shopping Expectations 2015
Report (dyn.com/consumer-survey), in the past 12
months nearly 70 percent of all consumers surveyed had
shopped online with retailers in other countries.
Chapter 1

6 Internet Performance For Dummies, Dyn Special Edition
✓✓ Consumer expectations evolve as quickly as the tech-
nology landscape. The adoption rate of mobile tech-
nology is one profound example of rapidly evolving
consumer expectations. In many countries, mobile web
browsing now exceeds traditional desktop browsing
and companies that don’t have websites built for mobile
devices lose business.
✓✓ Businesses must constantly evaluate their investments
in technology. Three-to five-year technology refresh
cycles driven by “useful life” financial definitions are
becoming irrelevant. Paradoxically, most technology
today is built to last for many years, but technology
changes so quickly that a three-or five-year refresh cycle
may limit innovation and place your business at a strate-
gic and competitive disadvantage.
✓✓ Growth and reliance on the global Internet have
created demand for Internet Performance. Nearly 3
billion people (40 percent of the world’s population), use
the Internet — and the next 3 billion are quickly coming
online. Today, everyone relies on the Internet for global
commerce, data sharing and exchange, and critical
infrastructure (such as transportation and utilities). The
Internet of Things (IoT) is rapidly evolving and will create
many innovative new uses for the Internet of the future.
Defining Internet Performance
Internet Performance means different things to different
people. Ultimately, Internet Performance is defined by the
end‐to‐end user experience for an Internet user who accesses
a company website or application. Potentially thousands
of variables can affect that experience: from the end user’s
device hardware and operating system to the company’s back-
end web server infrastructure — and everything in between.
In this book, I focus on the “in between” — often depicted as a
nebulous cloud labeled “Internet” on network diagrams.
Companies have long thought about how they connect to
their customers. They should, however, be thinking about
how their customers connect to them. Thus, Internet
Performance is defined by what happens after an end user
has opened a web browser and entered a website address;

Chapter 1: What Internet Performance Is and Why It Matters 7
traversed a network’s switches, firewalls, routers and various
other devices; and is now on her merry way to your website
or Internet‐facing application. However, this “before” stage
happens before the user has started traversing your net-
work’s switches, firewalls, routers, and various other devices
to get to the data center server that will actually render your
website or application.
Broadly, this “in between” encompasses the following:
✓✓ Internet Service Provider (ISP) networks
✓✓ Domain Name System (DNS) services
✓✓ Content Delivery Networks (CDNs)
✓✓ Cloud Providers
The characteristics that define Internet Performance include
the following:
✓✓ Availability
✓✓ Reachability
✓✓ Speed
✓✓ Security
✓✓ Cost efficiencies
✓✓ Increased revenue
History of the World
(Wide Web), Part I
Okay, although it’s probably not as entertaining as Mel
Brooks’s History of the World, Part I, I’ve included a brief his-
tory of the Internet. Understanding how the Internet has
evolved from its origins in the 1960s to become the Internet of
Things (IoT) underpinning today’s global economy is key to
understanding why Internet Performance matters.
If you haven’t seen Mel Brooks’ History of the World, Part I,
your homework assignment is to download or stream it on the
World Wide Web — which you’re about to learn all about —
and analyze how Internet Performance impacts how much
you enjoy the movie!

ARPANET
In the 1960s, the U.S. Department of Defense Advanced
Research Project Agency (DARPA) developed ARPANET, the
first network to use packet‐switching technology.
A packet‐switching network breaks data into small blocks,
or packets, and then transmits each individual packet from
node‐to‐node toward its destination. The individual packets
are then reassembled in the correct order at the destination,
thereby enabling a resilient, multipath communications net-
work instead of a single, end‐to‐end communication path.
By the end of 1969, a total of four computers were connected
to ARPANET. The challenge of connecting different computers
around the world in a single network would remain unrealized
for another decade. In the late 1970s, Stanford computer sci-
entist Vinton Cerf created the Transmission Control Protocol
(TCP) and, later, the Internet Protocol (IP). TCP/IP enabled
ARPANET and several other networks around the world to be
successfully connected, collectively becoming known as the
Internet in the late 1980s.
That is the way the Internet still works today. It is as simple
as that. This means that anyone can create information and
exchange information on how the Internet connects.
The World Wide Web
In 1989, Tim Berners‐Lee, a CERN physicist and computer sci-
entist, envisioned a web of information — consisting of a large
database with links to other electronic documents — that
could be shared on the Internet and, in 1991, the World Wide
Web was born. Later, Berners‐Lee founded the World Wide
Web Consortium (W3C). He no longer works for CERN, but in
2004 he was knighted by Queen Elizabeth II and became Sir
Tim Berners‐Lee.
Although the terms Internet and World Wide Web are popu-
larly used interchangeably, they’re not the same thing.
Technically, the Internet is a vast, global system of billions of
interconnected devices and networks. The World Wide Web
is a series of protocols — most notably, Hypertext Markup
Language (HTML), Hypertext Transfer Protocol (HTTP), and

Chapter 1: What Internet Performance Is and Why It Matters 9
Uniform Resource Locator (URL) — used to share information
on the Internet.
In 1993, students and researchers at the University of Illinois
Urbana‐Champaign’s National Center for Supercomputing
Applications (NCSA) introduced Mosaic, a graphical web
browser, which later became Netscape Navigator.
The dot.com boom – and bust
Simple and intuitive graphical web browsers (such as
Netscape Navigator and Internet Explorer), popular web
directories and search engines (such as Yahoo!, Altavista,
and Google), and low‐cost service providers (such as
CompuServe, Prodigy, and America Online) spurred rapid
growth of the World Wide Web and the dot.com boom at the
end of the 20th century.
The number of Internet users grew from just 14 million in 1993
to over 400 million in 2000 — a nearly thirtyfold increase in
just seven years! During that same period, thousands of start‐
up e‐commerce and dot.com companies were created. A new
idea‐based business model — one in which enterprising indi-
viduals could attract droves of global customers and eager
investors — emerged seemingly overnight.
In 2001, the dot.com boom suddenly went bust and investors
lost trillions of dollars. However, the dot.com bust wasn’t
an indictment of the World Wide Web or the global Internet
economy. Instead, it was a reminder that sound business and
financial fundamentals can’t be ignored.
Amazon, Facebook, iPhone, and
the Internet of Things
With nearly 3 billion Internet users worldwide in 2014, repre-
senting more than 40 percent of the world’s population, the
continued growth, popularity, and importance of the World
Wide Web to our modern global economy is evident.
The meteoric rise of e‐commerce goliaths (such as Amazon,
Rakuten, and Alibaba) and social media networks (such
as Facebook, Twitter, and Pinterest) is now fueled by rich,

dynamic content and high‐speed Internet access from a
dizzying array of WiFi networks and mobile devices (such as
iPhones and Android devices).
The Internet of Things (IoT) will connect nearly 50 billion
objects to the Internet by 2020 with embedded electronics,
sensors, and software in everyday “things” such as household
appliances, wearable technology, commodity items, and
consumer goods.
As our reliance on the World Wide Web continues to grow,
Internet Performance — a combination of availability, reach-
ability, reliability, security, and speed — becomes increas-
ingly critical for both businesses and consumers.

Internet101
In This Chapter
▶▶ Learning about ISPs on the level
▶▶ Connecting networks with peering and transit arrangements
▶▶ Looking up addresses with your little black book, uh . . . DNS
▶▶ Using a CDN for speed, resilience, and much more
In this chapter, you learn how to play well with others.
Actually, you learn how Internet Service Providers (ISPs)
play well with each other (mostly) to bring you the World
Wide Web — and why it matters. You also learn how the
Domain Name System (DNS) and Content Delivery Networks
(CDNs) work together to deliver better Internet Performance.
ISP Levels
It should come as no surprise that not all Internet Service
Providers (ISPs) are created equal. If you’re a business or resi-
dential customer of an ISP, you probably classify the different
ISPs based on criteria such as their performance, reliability,
and customer service, using a descriptive hierarchy based on
your personal experiences dealing with them: good, so‐so, or
poor, for example!
Companies such as ISPs watch speed, security, availability,
and cost very carefully — in fact, most of them are really good
at optimizing their infrastructure. But, they measure their
optimization of the Internet, not yours, and often these mea-
surements mismatch. The only company that can really mea-
sure the effectiveness of the Internet for your business is you.
Chapter 2

Although there is no formal authority that defines ISP tier
levels, there are three generally accepted network tier levels
(see Figure 2-1):
✓✓ Tier 1: An ISP that can reach the entire Internet via
its free or reciprocal peering arrangements (known as
settlement‐free peering and discussed later in this chapter)
with other Tier 1 ISPs. Current Tier 1 ISPs include the
following:
•• ATT (formerly SBC, formerly ATT)
•• CenturyLink (formerly Qwest and Savvis)
•• Cogent (formerly PSINet)
•• Deutsche Telekom
•• GTT (formerly Tinet)
•• Level 3 Communications (formerly Level 3 and
Global Crossing)
•• NTT Communications (formerly Verio)
•• OpenTransit (Orange)
•• Sprint
•• Tata Communications
•• Seabone (Telecom Italia Sparkle)
•• Telefonica Global Solutions (formerly TIWS)
•• TeliaSonera International Carrier
Figure 2-1: Peering and transit relationship between Internet provider tiers.

Chapter 2: Internet 101 13
•• Verizon Enterprise Solutions (formerly UUNET)
•• XO Communications
•• Zayo Group (formerly AboveNet)
✓✓ Tier 2: An ISP that peers with some networks without
fees, but still purchases IP transit or pays settlement fees
to reach a large portion of the Internet.
✓✓ Tier 3: An ISP that always purchases IP transit or pays
settlement fees to reach any portion of the Internet.
A Tier 1 network is a global network that can reach the entire
Internet over its own network backbone, or via the network
backbones of other Tier 1 networks. A Tier 1 ISP has recip-
rocal peering relationships with every other Tier 1 ISP that
permit them to use each other’s network backbones without
paying any transit or settlement fees — on the surface. In real-
ity, various payments are often exchanged between the vari-
ous Tier 1 ISPs, but these payments aren’t necessarily known
to the public.
If that definition of a Tier 1 network seems a little too straight-
forward and succinct, it’s because it is! In addition to global
Tier 1 networks, there are regional Tier 1 networks.
A regional Tier 1 network is the same as a global Tier 1 net-
work in all respects, except that it is confined to a specific
region, such as a geographic area within a country (for
example, the U.S. Southwest), an entire country (for example,
the United States), or an entire continent (for example, North
America). To extend its network beyond its specific region, a
regional Tier 1 network can establish peering arrangements
with, or purchase transit from, a global Tier 1 network, in
much the same manner as a Tier 2 network.
ISP Peering and Transit
Arrangements
The Internet is a patchwork of interconnections among ser-
vice provider networks. No single provider network com-
prises the Internet in its entirety. Instead, service providers

interconnect with other service providers in order to provide
access to all parts of the Internet for their customers. There
are essentially two types of interconnections:
✓✓ Peering (or settlement‐free): Links between two service
provider networks that are free.
✓✓ Transit: Links between two service provider networks
(or other entities) that aren’t free. An ISP’s customer
technically purchases transit from the ISP.
Bilateral peering arrangements exist for the mutual benefit of
the two cooperating networks in the relationship. However,
disputes can — and do — sometimes arise. When this hap-
pens, things get ugly (see the sidebar “Peering matters” later
in this chapter). Often a dispute will arise when one party
believes that an existing peering arrangement is providing
greater benefit to the other party than the benefit that is being
received. The aggrieved party may then attempt to convert
the peering arrangement to a transit link, forcing the other
party to pay for the interconnection. In extreme cases, the link
between the two networks may be unilaterally disconnected
(or depeered), effectively making large parts of the Internet
inaccessible to millions of customers in the case of a Tier 1
ISP. When this happens, other preexisting peering arrange-
ments in the depeered provider’s network may provide indi-
rect access to the portions of the Internet that are no longer
accessible (as long as the other party doesn’t disallow alter-
nate routing), but possibly along a less efficient or otherwise
less‐than‐optimal route.
Not all network outages are due to “technical difficulties.”
Oftentimes, an outage (or performance degradation) is the
result of a political or financial dispute between two service
providers. It’s important for you to have visibility of the cur-
rent and historical performance data of not only your ISP, but
also any upstream provider networks that your ISP relies on
for Internet access.

Peering matters
In 2005, Cogent and Level 3 had a
wee tiff over peering. Level 3 turned
off its connections to Cogent for
a few days as part of a strategy of
negotiating new terms of intercon-
nections. Politicians clamored to
offer new and ill‐considered regula-
tions for large‐carrier interconnec-
tion. In the process, politicians and
much of the media revealed their
limited understanding of how the
Internet works.
The organization, character, and
structure of network interconnec-
tions affect everything about how
the Internet works (and sometimes
doesn’t work). Peering (settlement‐
free interconnection) is a significant
part of that.
The evidence is that the market will
take care of maintaining the full con-
nectivity of the Internet, but it won’t
always do so on your timetable or
mine. Witness the Cogent/Level 3
peering dispute. Level 3 peered with
Cogent, apparently settlement‐free.
Level 3 is a default‐free network,
which just means that it is so large
that it connects to every other
default‐free network for free. There
is no company that Level 3 pays
for Internet transit. Cogent is in the
challenging position of being almost
default‐free. They have settlement‐
free interconnections from lots of big
carriers, but they still pay Verio for
transit to the ones that they’re miss-
ing (mostly Sprint). So when Level 3
disconnected Cogent, in theory,
Cogent could have reached Level 3
via Verio. They just chose not to. In
theory, Level 3 could have contracted
for transit to reach Cogent via some-
one else, too. They also chose not to.
And so during that period, custom-
ers who were single‐homed on the
Level 3 network (that is, customers
who had no connectivity from any
other provider) could not reach cus-
tomers who were single‐homed on
the Cogent network. That was a fair
number of people. It only lasted for a
few days and during that time both
parties were subject to intense pres-
sure, by the public and most impor-
tantly by their customers, to fix the
situation.
And so they did. Level 3 and Cogent
resolved their dispute. Peering dis-
putes are part of the life cycle of
the Internet. This dispute was not
unprecedented; it was not new; it
was not catastrophic. It will also not
be the last time two big networks go
head‐to‐head to decide what value
each of them gets out of the con-
nection between them. This isn’t an
aberration. This is how it is supposed
to work!

DNS
The Domain Name System (DNS) is a distributed Internet
database that maps human‐readable names to IP addresses,
allowing people to reach the correct website when entering a
website address (also known as a Uniform Resource Locator,
or URL). For example, the domain name dummies.com trans-
lates to the IP address of 208.215.179.139.
DNS speed and reliability are critical to the performance and
availability of your website and the success of your online
business. Every visitor’s first interaction with your website
begins with a series of DNS queries. Poor DNS performance
can lead to subpar customer experiences and lost business.
Although the speed of DNS responses is important, DNS can
also be used to route end users to the best web server loca-
tions (such as a data center or cloud provider) based on their
geographic locations. Doing this properly often impacts end‐
user performance on an even greater scale.
DNS is somewhat analogous to a contact list on your phone.
Your contact list maps phone numbers to the names of busi-
nesses and individuals and, in a similar manner, DNS maps IP
addresses to the names of websites. When you want to call
someone, you begin by finding and selecting their name in a
contact list, and then press the Call button. Similarly, when
you want to visit a website, you begin by typing the name of
the website, such as www.dummies.com, into a web browser.
The browser sends a DNS request to a DNS server to resolve
the website address to an IP address, and then connects to
the desired website. To appreciate how important DNS is,
imagine deleting the contact list on your phone and then
trying to get in touch with someone by entering the phone
number you memorized for that person.
Many companies rely on free or low‐cost DNS services pro-
vided by Internet Service Providers (ISPs), hosting provid-
ers, or domain name registrars. However, organizations that
understand the importance of DNS to the end user experience
use managed DNS services to ensure the following:

✓✓ Continuous availability
✓✓ Global reachability
✓✓ High performance
✓✓ Resilience
✓✓ Scalability
✓✓ Security
✓✓ Technical expertise and support
CDNs
A Content Deliver Network (CDN) is a system of distributed
servers that deliver web content (such as high‐resolution
images and streaming videos) to a user based on the following:
✓✓ Geographic location of the user
✓✓ Origin of the webpage
✓✓ Current availability and load of a content delivery server
CDNs speed the delivery of content for websites with high traf-
fic volumes and global reach. A CDN caches the content and
images of a subscriber website to a network of servers that are
dispersed at different geographic locations around the world.
When a website visitor requests a webpage that is part of
a CDN, the request is redirected from the originating site’s
server to a server in the CDN that is closer to the visitor to
deliver the content. The CDN will also communicate with the
originating server to deliver any content that has not been
previously cached. Generally, the closer the CDN server is to
the visitor geographically, the faster the content will be deliv-
ered to the visitor.
CDNs are particularly effective for optimizing content to
mobile devices and for handling large surges in web traffic (for
example, due to sporting events, online ticket sales, and sales).
CDN deployments are surging as organizations from web and
Fortune 1000 enterprises to startups and small‐to‐medium
businesses (SMBs), connect with customers and derive more
revenue from the web.

As of June 2014, more than 50 percent of the Alexa 1000 web-
sites (a measurement of the world’s most heavily trafficked
websites) use a CDN.
This high adoption rate demonstrates that CDN technol-
ogy is now a basic underlying infrastructure component for
high performance websites. Top CDNs among the Alexa 1000
include Akamai, Amazon CloudFront/AWS, Edgecast, lxdns.
com, Fastly CDN, MaxCDN, Level 3, ChinaCache, Xinnet, and
Limelight.
To learn about optimizing the use of CDNs, go to dyn.com/
cdn-needs.
Five questions to ask a CDN provider
Selecting a CDN provider is an
important decision. If you don’t do
your due diligence, you may get a
service that doesn’t quite fit your
needs, you could end up paying too
much for services you don’t need,
or you may not get the best perfor-
mance in the regions that matter
most to your business.
Knowing the answers to the following
questions before you start the evalu-
ation process will help you find the
right CDN provider for your needs.
1. What regions are most important
for your website to perform well in?
Not all websites have the same
audiences. If you have a globally dis-
persed group of visitors, your CDN
needs will be different from those
of a website that gets all of its traf-
fic from a single region. Know which
regions are most important to your
website. You may want to use mul-
tiple CDNs to leverage the best per-
forming solution in specific areas.
2. Is your content mostly dynamic or
static?
CDNs are great for caching and
loading relatively static web images
or style sheets. Dynamic content
that gets updated frequently may be
better hosted on premise. If you do
host dynamic content with a CDN,
find a provider that can quickly adapt
to any changes you may need.
3. What’s best for your industry?
Some CDN providers have extensive
experience working with particular
industries and have built additional
features or security measures that
align to the specific needs of those
industries. Some create industry‐
specific bundles to address the
specific requirements of a particu-
lar industry. If you have security or
regulatory compliance requirements,
find a provider with extensive expe-
rience in your industry to best meet
your needs.

4. What extra features do you need?
Depending on the nature of your
website, you may need special
features such as additional security
capabilities, video or image com-
pression, or mobile optimization.
Some CDNs may be better suited to
provide custom features, so deter-
mine your specific needs and dis-
cuss them with potential providers.
5. Do you need multiple CDN
providers?
You may also find yourself needing
more than one CDN provider to take
advantage of cost savings, better
regional coverage, or additional fea-
tures. In these cases, an indepen-
dent DNS provider can help you load
balance your website traffic among
multiple CDNs. However, some CDN
providers make it difficult to use their
CDN without also using their DNS —
be careful about choosing a provider
that requires you to use their other
services because this may limit your
ability to create a best‐of‐breed
solution. Instead, find a vendor‐
agnostic provider that doesn’t lock
you into their solution in case your
needs change.

Website,Application,and
ServiceDependencies
In This Chapter
▶▶ Understanding how websites work
▶▶ Getting the most out of service‐level agreements
In this chapter, you learn how websites work (at a very
high level) and how to ensure your ISP is performing to
standards.
How Websites Work
As discussed in Chapter 1, thousands of variables can affect
the end users’ web experience from their browser to your
website.
When a user enters a website address in her browser, as
many as 10 to 20 DNS requests are sent to a DNS server that
has been specified for that user’s network (see Chapter 2 for
a discussion of DNS). The DNS server answers these queries
with the IP addresses of the various endpoints (web servers)
that comprise your website. This is the first step of the jour-
ney to your website.
Poor website performance often results from routing an end
user to a less‐than‐optimal endpoint. Sending an end user to
a suboptimal endpoint will affect her entire session — page
after page, downloaded image after downloaded image. That
endpoint could be geographically far away from the end user,
or it could be located in a poorly performing data center.
Chapter 3

Either way, DNS can be leveraged to route end users to a
better performing location. Sending an end user to a “bad”
endpoint is bad for business — it negatively impacts their
entire experience with your website.
Dyn’s Global Consumer Online Shopping Expectations 2015
Report found that nearly 65 percent of all consumers sur-
veyed aren’t willing to wait more than three seconds for a web
page to load.
Over the past several years, Content Delivery Networks
(CDNs) have become increasingly popular. CDNs (discussed
in Chapter 2) cache static webpage content on servers around
the world. A single web page load often requires multiple DNS
requests, which creates multiple opportunities to optimize
Internet Performance by routing an end user to the most opti-
mal endpoints, or multiple risks to Internet Performance if
an end user is routed to suboptimal endpoints. For example,
static images or video can be pulled from a server that is geo-
graphically much closer to a user, which improves end user
performance. Dynamic content, such as the results of a data-
base query or a website search engine, can be delivered by
one of the company’s web servers from the most optimal data
center for that particular session.
Finally, all of these DNS requests and responses must be routed
across numerous interconnected networks to deliver the con-
tent or asset to the end user. Each network can adversely affect
end‐user performance, both directly and indirectly. A slow net-
work along the direct path between the end user and the com-
pany’s website will obviously have a negative impact on the
end‐user’s experience. But less obvious, a slow network host-
ing a CDN’s servers in Brazil, for example, can also have a nega-
tive impact on the end‐user experience. Thus, it’s important for
a business to understand which networks and external factors
its customers will rely on to reach the company’s website.
Managing Service‐Level
Agreements (SLAs)
SLAs are essentially contracts between a service provider and
a customer guaranteeing a minimum level of performance.
SLAs may exist between any sort of service provider and

Chapter 3: Website, Application, and Service Dependencies 23
customer (for example, between an IT help desk and a com-
pany’s employees), but the focus here is on Internet Service
Providers (ISPs), cloud providers, CDNs, and their business
customers.
An SLA is usually included as an addendum to a contract,
rather than a contract itself.
Typical provisions in an SLA will address minimum Internet
Performance standards in terms of speed, latency, and avail-
ability (or uptime). Additionally, the SLA will define remedies
(SLA credits) for SLA violations and the process for request-
ing an SLA credit.
It is important to know that there is typically little to no room
for negotiation of a third‐party service provider’s SLA terms.
The service provider will correctly argue that it is impossible
for it to maintain different SLA terms for each of their several
thousand customers. Still, SLA negotiation is an important
part of the selection and provisioning process and you should
fully understand your service provider’s SLA provisions
before signing a contract.
A common argument against SLAs is that the remedies pro-
vided are meaningless. Website downtime for many busi-
nesses directly results in lost revenues. Indirect losses can
result from damage to your brand reputation due to a website
outage. Online consumers (mistakenly) believe that success-
ful companies don’t have website issues. Thus, an outage that
results in three hours of website downtime, for example, for
an e‐commerce company that averages $5,000 in online sales
per hour theoretically costs the company $15,000 in lost sales.
The remedy for a three‐hour outage is typically an invoice
credit equal to the cost of three hours of monthly Internet
service — probably a few dollars at most. Just as a service
provider is unlikely to modify the performance terms of its
SLA, it isn’t feasible or practical to provide different remedies
based on theoretical losses for each of a service provider’s
individual customers — a single outage event could bankrupt
even the largest service provider!
However, SLAs are important nonetheless. An SLA demon-
strates how seriously a service provider is committed to its

established performance standard and to customer service.
Consider, for example, the following questions:
✓✓ When an SLA violation inevitably occurs, does the
service provider self‐report the violation or is it the
customer’s responsibility to report an outage? Some
service providers define an outage start time as the time
that the customer logs a trouble ticket with the service
provider. Thus, if you don’t report an outage — it never
happened!
✓✓ How difficult is it to claim an SLA credit? Some service
providers will proactively and automatically initiate an
SLA credit when a violation has occurred (rare). Other
service providers will require the customer to request an
SLA credit in order to initiate a process that could take
months (more common).
An SLA remedy that can sometimes be negotiated and gives
the SLA “teeth” is an early termination clause. Such a remedy
allows the customer to terminate a service contract without
penalty if an SLA violation (usually several SLA violations)
occurs. That way, you won’t be stuck with a bad service
provider for a three‐year term!
You also need to understand — in business terms — what the
specific performance standards will mean to your business.
Some performance standards to understand include the
following:
✓✓ Availability (or uptime): Uptime is usually expressed to
some thousandth of a percentage point above 99 percent.
Although that sounds really impressive, think of uptime
like hand sanitizer. Most hand sanitizers claim to kill 99
percent of all germs. That’s great, except that there are
millions of germs that can make you sick, so that still
leaves at least 100,000 germs on your hands! 99.9 percent
uptime means nearly 9 hours of downtime per year. Can
your business afford 9 hours of downtime? Surprisingly,
your answer might actually be yes. 99.999 percent uptime
may be cost prohibitive, and 9 hours a year is less than
an hour per month. The outage might also occur at
3 o’clock in the morning, thus minimally impacting your
business. Although even if it’s 3 a.m. in your time zone,
it’s going to be noon somewhere.

Chapter 3: Website, Application, and Service Dependencies 25
✓✓ Performance: Performance includes characteristics
such as speed, reliability, loss, latency, and jitter, among
others. Make sure your connection is fast enough to
support your business. Reliability isn’t the same thing
as availability. An Internet connection that is constantly
flapping (up and down) isn’t reliable. Packet loss can
cause data corruption issues if you’re hosting a data‐
intensive application with a backend database, for
example. Packet loss, latency, and jitter may also cause
unacceptable voice quality if you’re using voice‐over‐IP
(VoIP), for example in a customer service call center.
✓✓ Maintenance windows: Make sure you know when stan-
dard maintenance windows occur (is it during a peak
period for your business?) and the service provider’s
notification responsibilities. Again, it is unlikely, imprac-
tical, and unfeasible for a service provider to schedule
maintenance windows around each of their customer’s
unique business requirements, but if the standard main-
tenance window occurs at a time that is unacceptable for
your business, you need to have a mitigation strategy or
find a different service provider.
CNBC uses Dyn Managed DNS to
improve Internet Performance
CNBC provides business and finan-
cial news for hundreds of millions of
people around the world. Like many
other large websites, CNBC relies on
a content delivery network (CDN) to
provide rich media content — such
as streaming charts and video, and
Rich Site Summary (RSS) feeds — to
optimize and enhance the website
user experience. In 2012, CNBC’s
Director of Platforms, Rashid
Karimov, began researching solu-
tions to improve CNBC’s website
Internet Performance. CNBC’s eval-
uation and success criteria included
the following:
✓✓ Improve response time
✓✓ Have better control over web
traffic (real-time reporting,
change management, and
alerting)
✓✓ Use internal data centers and
infrastructure more efficiently
✓✓ Shield users from any troubles at
the origin infrastructure
✓✓ Be cost effective
CNBC selected Dyn’s geolocation
load-balancing solution powered by
an Anycast network. The distributed
(continued)

nature of Dyn’s domain name system
(DNS) service and flexible traffic bal-
ancing rules were key components
for achieving CNBC’s objective: to
steer users to their closest origin
point based on location.
To determine user locations and
direct them to their geographi-
cally closest origin point, Dyn uses
border gateway protocol (BGP) rout-
ing to advertise routes to the same
IP addresses from multiple points
of presence. When a user opens
a browser and visits www.cnbc.
com, a DNS request is sent to the
closest Dyn data center. The DNS
server cluster infers that the request
is coming from a user in the same
geographic area as the DNS clus-
ter that receives the request and,
based on that information and a set
of CNBC‐configured traffic rules,
the user’s browser is directed to the
closest origin point for www.cnbc.
com. For origin points, CNBC uses its
own data centers, each with multiple
gigabits of egress capacity, on the
U.S. east and west coasts.
The Dyn solution has resulted in
numerous benefits, including the
following:
✓✓ 30 percent (approximately
1 second) faster page load times,
as reported by Keynote
✓✓ 80 percent less CDN traffic
volume — and corresponding
CDN cost savings
✓✓ 80 percent reduction in load on
content management systems
(CMS), which has improved
overall stability of the CMS envi-
ronment
✓✓ Complete, real‐time views of
traffic down to RPS (requests
per second), response time,
number of connections, cached
responses, and more
✓✓ Real‐time reporting, charting,
and alerting on traffic para
meters
✓✓ Better utilization of data center
capacity
✓✓ Instantaneous ability to change
caching rules or load distribution
Other features of the Dyn Managed
DNS solution include automatic
monitoring, failover, alerting, and
traffic reporting — all via a flexible
and easy‐to‐use web portal.
(continued)

InternetPerformanceinthe
EyesofYourCustomers
In This Chapter
▶▶ Getting to your website and applications
▶▶ Feeling the need for speed
▶▶ Keeping it secure
The stakes for Internet sales are skyrocketing for retailer
and e‐commerce executives around the world. Businesses
have been struggling to keep pace with consumer demands
for years— regardless of where, when, or how customers are
shopping. Technology advancements, while giving retailers and
e‐commerce companies new ways to reach their customers,
have been just as much of a blessing as a curse. Ensuring the
performance of your web properties is your responsibility.
Whether the issue is with your cloud provider, your CDN,
or a third party application, your customers will ultimately
blame you if something goes wrong.
Consumers now, more than ever, have the power of choice.
Winning (and keeping) customers is getting harder, and one
hiccup — an unavailable or slow website, hard‐to‐find prod-
ucts, or security shortcomings — could send a would‐be
customer to shop elsewhere and possibly never return to
your website.
In this chapter, you learn what’s important to your customers
when it comes to Internet Performance.
Chapter 4

Always Reachable
First and foremost, your customer expects your website to be
reachable: 24 hours a day, 7 days a week, 365 and one‐quarter
days a year!
Reachability and availability are closely related, but different.
Reachability means a user can get to your website over the
Internet. Routing and DNS are two key components of reach-
ability. Availability means your website is actually there (up
and running) when a user gets to your web servers!
Companies have traditionally focused on availability, which
is measured in uptime. Whether or not end users can actually
reach their websites from all of their various market regions
isn’t something most companies have spent a lot of time or
effort monitoring and investigating. If end users in a particular
large market — for example, Canada — can’t reach a compa-
ny’s websites, it’s not necessarily the company’s fault (“all of
our services are up and running,” in other words “available”)
but the company will suffer the business consequences
nonetheless.
Always Fast
Three seconds can be the difference between a loyal cus-
tomer and a lost customer.
The majority of consumers don’t abandon online shopping
sprees because they change their minds or run out of time to
make their purchases. Slow‐loading websites and skepticism
around security get in the way of completing a purchase for
nearly two thirds of consumers globally, according to Dyn’s
2015 Report: Global Consumer Online Shopping Expectations.
According to this report, two‐thirds of global consumers leave
websites at least 25 percent of the time without buying any-
thing because they’re tired of waiting for the website to load.
Retailers and e‐commerce companies lose sales and the
potential of life‐long customers because of poor performing
websites.

Chapter 4: Internet Performance in the Eyes of Your Customers 29
To compete and win in the global online shopping world,
online retailers and e‐commerce companies need to do the
following:
✓✓ Improve website performance. Because every cus-
tomer’s first visit to your website starts with multiple
DNS queries, avoid making your customers wait for your
website to load by resolving DNS queries faster and
routing customers to the most optimal endpoint for
performance.
✓✓ Create a seamless omnichannel experience. Whether
your customers are accessing your website from home
on their computers or on the go with their mobile
devices, ensure that they always experience the same
great performance.
✓✓ Stay on top of Internet trends. Don’t let avoidable
slowness or website outages happen. Use Internet
Performance tools to intelligently monitor and analyze
current Internet conditions and help you make important
infrastructure decisions to improve your overall website
performance.
✓✓ Remain consistent across borders. Geolocation load
balancing allows you to route customers based on their
location (for example, country, state, or province). With a
global network, your customers can expect to receive the
same performance from your website whether they’re at
home or traveling abroad.
Mobile users have a heightened sense of awareness regarding
performance issues when it comes to their devices (ironi-
cally enough, since people tend to have a decreased sense
of awareness of everything around them when using mobile
devices!). Thus, the mobility trend exacerbates the need for
speed.
Always Secure
Last, but certainly not least, your customers require your
website and applications to be secure. A security breach is
absolutely unacceptable and will cost you current customers,
prospective customers, and customers that had never even
heard of your company before a publicized security breach.

Companies have traditionally focused their security efforts on
securing their network or data center perimeter with security
infrastructure such as firewalls and intrusion prevention sys-
tems (IPSs). Many businesses now recognize the need to bol-
ster their security inside the firewall with technologies such
as advanced endpoint protection and innovative new security
techniques such as microsegmentation.
However, very little focus has been directed toward extend-
ing security beyond — or outside — the firewall. Attacks that
use techniques such as DNS hijacking or BGP (border gateway
protocol) hijacking are just as effective at destroying your
customers’ confidence and you brand reputation as a direct
attack against your web servers. In these types of attacks, an
attacker will simply redirect your customers’ web traffic to
a web server that it controls. The attacker may then lure the
user into entering personal information and/or financial infor-
mation, or use a drive‐by‐download to infect your customers’
endpoint devices with malware.
Similarly, a distributed denial‐of‐service (DDoS) attack can
cause your customer to lose confidence in your website or
applications, or simply frustrate them enough that they go
to your competitor’s website! One of the bigger motivators
around recent attacks has been to distract IT personnel while
the attackers conduct more malicious activities, such as data
theft. Another, often overlooked and less obvious risk with a
denial‐of‐service (DoS) attack is the likelihood of an attacker
exploiting a vulnerability. A DoS attack may, for example, use
an SQL injection to cause a buffer overflow on your database
servers, allowing the attacker to then gain shell access and
run an exploit to install malware on the server. Although
the immediate damage of the denial of service can be signifi-
cant, the long‐term damage to the compromised server may
go undetected for months or years, during which time an
attacker may harvest sensitive customer information or exfil-
trate other valuable data from your company.
To learn more about about DDOS mitigation, visit dyn.com/
understanding-ddos.

Chapter 4: Internet Performance in the Eyes of Your Customers 31
DNS security: Three ways that
hijacks can happen
There are three common techniques
used to redirect traffic through com-
promised DNS servers:
✓✓ The first is to perform a cache poi-
soning attack. Basically, attackers
attempt to inject malicious DNS
data into the recursive DNS serv-
ers that are operated by many
ISPs. These DNS servers are typi-
cally the “closest” to users from
a network topology perspective,
so the damage is localized to spe-
cific users connecting to those
servers. There are effective work-
arounds to make this impractical
in the wild, and good standards
like DNSSEC that provide addi-
tional protection from this type of
attack.
✓✓ The second method is to take over
one or more authoritative DNS
servers for a domain, and change
the DNS data. If an attacker were
to compromise authoritative DNS,
the effect would be global. Good
security practices like strong
passwords, two‐factor authen-
tication, IP ACLs (access control
lists), and good social engineering
training are effective at thwarting
these attacks.
✓✓ The third technique can be the
most difficult to undo. With this
technique, the attacker takes over
the registration of a domain and
changes the authoritative DNS
servers. What makes this attack
so dangerous is the TTL (time to
live). Changes of this nature are
globally cached on recursive DNS
servers for typically 86,400 sec-
onds, or a full day. Unless opera-
tors are able to purge caches, it
can take an entire day (some-
times longer) for the effects to be
reversed.

InternetPerformanceinthe
EyesofYourBusiness
In This Chapter
▶▶ Recognizing common fears in going to the cloud
▶▶ Maximizing revenues by maximizing Internet Performance
▶▶ Spending wisely to improve Internet Performance
▶▶ Maintaining the integrity of your brand
▶▶ Using the right tools to address Internet Performance challenges
In this chapter, you examine some of the challenges for
your business as they relate to Internet Performance and
how you solve them.
Common Cloud Adoption Fears
Cloud services are more popular than ever. IDC recently
reported that cloud services and infrastructure grew by 25
percent over 2014 reaching $100 billion. Yet, there is still hesi-
tation in the marketplace to make the move to the cloud.
Although many capitalization and speed‐to‐market benefits of
using cloud services exist, five common fears prevent compa-
nies from really going all‐in on cloud infrastructure.
✓✓ Losing control: By their very nature, cloud providers
obscure some details of their operating environment.
Services are geographically centralized and, therefore,
remote. Seeing the actual operations of the cloud service
Chapter 5

center is rare. Also, infrastructure is shared. HVAC (heat-
ing, ventilation, and air conditioning), systems, network
operations, network connections, and more are shared
across many clients. This, of course, is why cloud pro-
viders are so cost‐effective and customers are allowed a
certain amount of configurability. But this lack of detail
and specificity forces your company to trust the cloud
provider to deliver services to your expectations.
✓✓ Increased security threats: Security risk is closely
associated with the fear of losing control. By advertis-
ing cloud locations and centralizing customers, cloud
service sites are clear targets for security threats. Once
breeched, many companies are made vulnerable to
attack. There are over 1,000 domain hijacks a day and
many of them are happening with cloud providers.
Security threats can result in downtime, loss of reputa-
tion, loss of customers, and lost or stolen private
customer data.
✓✓ Weakened data protection: Perhaps the greatest fear of
all is combining lost control, security threats, and lost
data into a single nightmare scenario. Often, going to the
cloud means exposing data access to the Internet edge
at a place you don’t control. Stolen company and/or cus-
tomer data can cost millions of dollars in litigation alone.
✓✓ Poor performance and uptime: A recent study commis-
sioned by Dynatrace found that 45 percent of respon-
dents worried about loss of revenue due to downtime,
poor performance, and time to resolution of problems.
Plus, 51 percent were concerned these problems would
result in brand and customer loyalty erosion and 64 per-
cent were concerned that cloud performance bottlenecks
would result in a poor end‐user experience. These find-
ings point toward a general belief that slow is the new
downtime, and concerns that cloud implementations
might contribute to poor(er) performance.
✓✓ Fear of being tied to one vendor: Many companies begin
their journey to the cloud by migrating basic services
to a cloud provider, then slowly adding more business‐
critical services over time as trust and confidence in
the cloud provider is built. This ad hoc approach to
cloud adoption, rather than a strategically planned
cloud migration, often results in a company hosting all
its services with a single cloud service provider. This is

Chapter 5: Internet Performance in the Eyes of Your Business 35
unfortunate because many cloud companies specialize
and provide best‐of‐breed solutions in niche areas such
as Platform as a Service (PaaS), Software as a Service
(SaaS), and Content Delivery Networks (CDNs) specializ-
ing in video streaming, for example. Companies need
to strategically plan their move to the cloud and avoid
reliance on a single cloud vendor.
Revenue‐Driven Decisions
In today’s technology‐driven economy, Internet outages and
poor performance have a direct impact on your company’s
revenues and customer satisfaction. If your company’s web-
site and customer‐facing applications are unreachable or run-
ning slow, customers will take their business elsewhere.
Enterprise infrastructure and operations (IO) teams need
monitoring, analysis, and planning tools that enable them to
avoid service interruptions, reduce costs, deliver the best
possible online experience, and plan for current and future
needs. Such tools enable these teams to answer key Internet
Performance questions, including the following:
✓✓ Monitoring
•• How can I see Internet events that are compromis-
ing my customers’ paths to my website?
•• Are network changes affecting reachability?
•• Are my cloud partners meeting my performance
and availability expectations?
✓✓ Analysis
•• What are the root causes of our web‐facing perfor-
mance problems?
•• Are the problems inside or outside our networks?
•• How can I mitigate the effects of outages, hijacks,
and misconfigurations?
•• How can I create a consistent and reliable web-user
experience?

✓✓ Planning
•• How do network service providers compare in
terms of performance?
•• How do cloud service providers and their location
choices compare in terms of performance?
•• Where should we locate our data centers to best
serve our customers?
•• How do I best serve my enterprise with Software as
a Service (SaaS), Infrastructure as a Service (IaaS),
and Platform as a Service (PaaS) solutions?
Comprehensive monitoring, analysis, and planning tools
enable IO teams to more effectively support the business.
Agility is key to a sustainable competitive advantage. Too
often, new ideas for products and services aren’t brought to
market quickly enough because the supporting infrastruc-
ture can’t adapt and scale to meet the needs of the business
quickly enough. Whether you need to plan for the launch
of a new web‐based service or a new application that relies
on email delivery, Internet Performance tools can help your
enterprise IO teams maximize the performance of your web-
site and Internet applications, so that you can maximize
revenues and stay ahead of your competition.
Efficient Spend on Internet
Resources
Today’s business environment is challenging. The competitive
landscape is rapidly and constantly evolving while capital and
operating budgets for most companies are stagnant or shrink-
ing. There is always tremendous pressure to maximize the
value of every IT dollar spent.
Many companies have embraced a cloud strategy for key
technology initiatives. With the widespread adoption of
cloud‐based services, enterprise IO teams can now strate-
gically evaluate which services are best delivered in‐house
and which are more effectively delivered by hosted service
providers. By leveraging Internet Performance services, you
can confidently migrate critical functions to the cloud and
improve your operational capabilities by focusing on the
projects that are most critical to your business.

Protect Your Brand
Poor Internet Performance can result not only in lost revenue
but also damage to your brand. Online customers expect busi-
ness websites to always be reachable, fast, and secure (see
Chapter 4).
A major component of Internet Performance is business con-
tinuity planning. Business continuity planning is closely related
to disaster recovery planning, but is specifically focused on
what your company will do to keep the business running in
the event of an outage or disaster. Disaster recovery planning
focuses on the steps necessary to restore the business to its
normal operating condition.
Business continuity planning often begins with a business
impact analysis (BIA) to determine what effect the loss of spe-
cific systems and applications will have on your business. A
BIA helps you prioritize your business continuity efforts and
identify potential dependencies among systems, applications,
data centers, networks, and service providers that need to be
addressed in your business continuity plan.
Key elements of an effective business continuity plan must
address the following:
✓✓ Third‐party dependencies: Ensure that the partners you
rely on have developed plans of their own to ensure your
business can operate after an event or disaster.
✓✓ Active failover: You can automatically reroute your
Internet traffic to another fully operational data center
and minimize or eliminate the business impact of an
event or disaster.
✓✓ Redundant services: Eliminate or mitigate single points
of failure throughout your infrastructure. For example,
DNS services should not be located in the same data cen-
ters or hosted by the same cloud providers as your appli-
cations in order to ensure you can route Internet traffic
around outages.

Don’t leave your customers in the dark
if your website goes dark
An effective business continuity
plan is important for every business,
and a critical element of any busi-
ness continuity plan is how you will
communicate information to your
customers.
If all else fails (failover and redun-
dancy), be sure you can still commu-
nicate with your customers. Create a
status page to use as a last resort if
your website is unavailable. Honest
communication with your custom-
ers about what is going on can keep
their experience positive, rather than
greeting them with an error page.
For (hopefully) obvious reasons, you
should host your status page through
a different provider than where you
normally host your website. What
good is a status page that goes down
with the rest of your site? If your site
goes down, you can easily failover
to this status page (with a little DNS
magic) and alert your customers of,
well, your status.
Finally, be prepared to communicate
with your customers via other com-
munication channels. Some com-
panies do a social failover, which
means that they failover directly
to their Twitter or Facebook feed.
If you’d prefer to provide a more
deliberate explanation of the situa-
tion, simply referencing your social
pages on your status page may be
a good solution. For example, when
Hurricane Sandy hit the U.S. East
coast, many of the affected web-
sites went to their social channels to
remain in contact with their custom-
ers and fans.
Addressing Internet Performance
Challenges
Performance management tools, such as application per-
formance management (APM) and network performance
management (NPM), can help organizations address con-
cerns about moving to the cloud, web‐facing applications
and services performance, and other business challenges
discussed in this chapter. In addition to these tools, Internet
Performance tools are a critical component to help com-
panies monitor, control, and optimize their infrastructure
assets (see Figure 5-1).

When you go to the cloud, the cloud provider becomes the
Internet presence to your customers. How your customers
reach your selected cloud instance is, in large part, the source
of the five fears exposed earlier in this chapter. Internet
Performance tools can help you monitor all of the paths that
your customers take to get to your cloud assets. With Internet
Performance tools, you can see outages, redirects, perfor-
mance problems, and security risks. If there is a man‐in‐the‐
middle hijack on a route from one of your key markets, you
can see it and immediately mitigate the attack. Even though
you don’t own these routes (they are the routes going to your
cloud provider), you can nevertheless see the problem and
reroute your customers to a secondary destination.
When you integrate Internet intelligence with DNS control,
you gain a powerful combination that enables you to optimize
your infrastructure. Not only can it help you see problems
earlier and more distinctly, but you also gain the indepen-
dence to measure your partners more completely and choose
multiple cloud service destinations based on performance,
availability, and reachability. This capability, in turn, helps
drive revenue, optimize your infrastructure spend, and pro-
tect and enhance your brand image. For example, a cloud
instance from one provider might be your best choice for
Southeast Asia, while another one is your best choice for
Latin America. Monitoring performance across all of your
service providers enables you to make the best routing
choice and gives you the control to send customers to a cloud
provider based on geography, performance, SLA, and more,
thereby optimizing your infrastructure and maximizing your
customer experience.
Figure 5-1: Internet Performance tools enable organizations to monitor,
control, and optimize their infrastructure.

TenKeyInternet
PerformanceTakeaways
In This Chapter
▶▶ Recognizing what you need to do to improve Internet Performance
In this chapter, I present ten Internet Performance take-
aways for your reading pleasure!
Implement Managed DNS
IT staff are refocusing their efforts on what their core compe-
tencies are and recognizing that running DNS is more compli-
cated and more error prone, while the dependence on good
name resolution is much greater. Because so many services
depend on accurate name‐to‐computer mapping, many admin-
istrators are hesitant to alter any part of their DNS infrastruc-
ture, making the system inflexible to new applications and
new services.
Enterprises need to understand the soft costs of running DNS
and the staff time to maintain DNS. Requests to change DNS
entries can take days or weeks to process. Costly outages
affect all web and email services. IT staff time is better spent
on rolling out key projects.
So what does managed DNS offer the enterprise?
✓✓ Websites, email, and other online services achieve better
uptime
✓✓ Visitors get to websites faster
Chapter 6

✓✓ Computing resources are optimized through global
server load balancing
✓✓ End‐user performance is improved through proper geolo-
cation
✓✓ End users get DNS‐based DDoS protection and other
security benefits that are very difficult to get from their
IT teams.
✓✓ IT resources are freed up for core IT services and
projects
To learn more about managed DNS providers, go to dyn.com/
dns-providers.
Provide Redundant Access to
Your Cloud Services
Like any other business‐critical IT service, cloud‐based IT
services must be resilient with no single points‐of‐failure.
Provisioning redundant network access from multiple service
providers will help to ensure your cloud‐based services are
always reachable by your users and customers.
Measure Cloud Performance to
Key Markets
Internet Performance varies from network to network and
region to region. Understand where key markets for your
business are located, which provider networks service those
markets, and how they perform both historically and in real
time. Likewise, measure and monitor the performance of your
various cloud service providers in your key markets.
Explore Problem Mitigation
Before It Happens
Internet Performance tools enable enterprise infrastructure
and operations (IO) teams to proactively monitor and ana-

Chapter 6: Ten Key Internet Performance Takeaways 43
lyze network issues before they become network problems.
This means less downtime for your company’s website and
Internet applications which, in turn, means less lost revenue,
less customer churn, and less damage to your brand.
Whether selecting a data center location or your next cloud
provider location, Internet Intelligence gives you the insight to
do this intelligently, thereby avoiding some issues altogether.
Catch Problems Early and
Update DNS
When problems in the network happen, they can propagate
rapidly and cause major outages. Internet Performance tools
enable you to detect these problems quickly and resolve them
before they can spread across your infrastructure. The capa-
bility to intelligently route around problem networks helps
you avoid performance problems and outages that can impact
your website and Internet applications.
Improve the End‐User Experience
Ultimately, it’s your customers’ website experience that
matters most. Internet Performance tools help you identify
problem areas throughout the Internet, including with cloud
providers and CDNs, and intelligently route around them.
For your customers, reachability, speed, and security are
critical. Today’s online consumer expects the average website
to load in three seconds or less. If your website can’t meet
that standard, your customers will take their business to your
competitors’ websites.
Enforce SLAs
Service‐level agreements (SLAs) define the minimum per-
formance standards for a service provider to its customers.
Internet Performance tools provide you with the data you
need to hold your service providers accountable to that
standard.

Maximize Asset Utilization
Today’s challenging business climate and tight capital and
operating budgets require IT managers to maximize the value
of every IT investment. Internet Performance tools enable IT
managers to optimize and plan their network capacity needs
and infrastructure requirements, thereby ensuring you don’t
purchase additional capacity or infrastructure too early — or
too late.
Increase Revenues
In much the same way that traditional brick‐and‐mortar
stores measure the throughput of their point‐of‐sale (POS)
and credit card processing systems, online businesses and
e‐commerce retailers must constantly measure Internet
Performance. Poorly performing websites and outages mean
lost revenues and brand damage. Conversely, a well‐designed
and high‐performing website can drive additional revenues.
Particularly, for mobile shoppers, speed is the name of
the game.
Focus on Core Competencies
DNS is a basic service that is critical your business, and to
ensuring a positive end‐user experience, but many IT orga-
nizations take DNS for granted. However, DNS servers are
often vulnerable to attack and prone to configuration errors.
Managed DNS takes this basic, but critical function, off IT’s
plate so it can focus on other value‐added services for the
business.
Likewise, cloud‐based services can transform the delivery of
IT services and enable business agility. The role of IT then
becomes that of a service broker, which gives more time back
to IT to work on other core IT projects and services.

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Internet Performance for Dummies

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