[Infowarrior] - Striving to Map the Shape-Shifting Net

[Richard Forno]

March 2, 2010
Striving to Map the Shape-Shifting Net
By JOHN MARKOFF
http://www.nytimes.com/2010/03/02/science/02topo.html?hpw=&pagewanted=print
SAN FRANCISCO — In a dimly lit chamber festooned with wires and hidden  
in one of California’s largest data centers, Tim Pozar is changing the  
shape of the Internet.

He is using what Internet engineers refer to as a “meet-me room.” The  
room itself is enclosed in a building full of computers and routers.  
What Mr. Pozar does there is to informally wire together the networks  
of different businesses that want to freely share their Internet  
traffic.

The practice is known as peering, and it goes back to the earliest  
days of the Internet, when organizations would directly connect their  
networks instead of paying yet another company to route data traffic.  
Originally, the companies that owned the backbone of the Internet  
shared traffic. In recent years, however, the practice has increased  
to the point where some researchers who study the way global networks  
are put together believe that peering is changing the fundamental  
shape of the Internet, with serious consequences for its stability and  
security. Others see the vast increase in traffic staying within a  
structure that has remained essentially the same.

What is clear is that today a significant portion of Internet traffic  
does not flow through the backbone networks of giant Internet  
companies like AT&T and Level 3. Instead, it has begun to cascade in  
torrents of data on the edges of the network, as if a river in flood  
were carving new channels.

Some of this traffic coursing through new channels passes through  
public peering points like Mr. Pozar’s. And some flows through so- 
called dark networks, private channels created to move information  
more cheaply and efficiently within a business or any kind of  
organization. For instance, Google has privately built such a network  
so that video and search data need not pass through so many points to  
get to customers.

By its very nature, Internet networking technology is intended to  
support anarchic growth. Unlike earlier communication networks, the  
Internet is not controlled from the top down. This stems from an  
innovation at the heart of the Internet — packet switching. From the  
start, the information moving around the Internet was broken up into  
so-called packets that could be sent on different paths to one  
destination where the original message — whether it was e-mail, an  
image or sound file or instructions to another computer — would be put  
back together in its original form. This packet-switching technology  
was conceived in the 1960s in England and the United States. It made  
delivery of a message through a network possible even if one or many  
of the nodes of the network failed. Indeed, this resistance to failure  
or attack was at the very core of the Internet, part of the essential  
nature of an organic, interconnected communications web with no single  
control point.

During the 1970s, a method emerged to create a network of networks.  
The connections depended on a communication protocol, or set of rules,  
known as TCP/IP, a series of letters familiar to anyone who has tried  
to set up their own wireless network at home. The global network of  
networks, the Internet, transformed the world, and continues to grow  
without central planning, extending itself into every area of life,  
from Facebook to cyberwar.

Everyone agrees that the shape of the network is changing rapidly,  
driven by a variety of factors, including content delivery networks  
that have pushed both data and applications to the edge of the  
network; the growing popularity of smartphones leading to the  
emergence of the wireless Internet; and the explosion of streaming  
video as the Internet’s predominant data type.

“When we started releasing data publicly, we measured it in petabytes  
of traffic,” said Doug Webster, a Cisco Systems market executive who  
is responsible for an annual report by the firm that charts changes in  
the Internet. “Then a couple of years ago we had to start measuring  
them in zettabytes, and now we’re measuring them in what we call  
yottabytes.” One petabyte is equivalent to one million gigabytes. A  
zettabyte is a million petabytes. And a yottabyte is a thousand  
zettabytes. The company estimates that video will account for 90  
percent of all Internet traffic by 2013.

The staggering growth of video is figuring prominently in political  
and business debates like the one over the principle of network  
neutrality — that all data types, sites and platforms attached to the  
network should be treated equally. But networks increasingly treat  
data types differently. Priority is often given to video or voice  
traffic.

A study presented last year by Arbor Networks suggesting that traffic  
flows were moving away from the core of the network touched off a  
spirited controversy. The study was based on an analysis of two years  
of Internet traffic data collected by 110 large and geographically  
diverse cable operators, international transit backbones, regional  
networks and content providers.

Arbor’s Internet Observatory Report concluded that today the majority  
of Internet traffic by volume flows directly between large content  
providers like Google and consumer networks like Comcast. It also  
described what it referred to as the rise of so-called hyper giants —  
monstrous portals that have become the focal point for much of the  
network’s traffic: “Out of the 40,000 routed end sites in the  
Internet, 30 large companies — ‘hyper giants’ like Limelight,  
Facebook, Google, Microsoft and YouTube — now generate and consume a  
disproportionate 30 percent of all Internet traffic,” the researchers  
noted.

The changes are not happening just because of the growth of the hyper  
giants.

At the San Francisco data center 365 Main, Mr. Pozar’s SFMIX peering  
location, or fabric, as it is called, now connects just 13 networks  
and content providers. But elsewhere in the world, huge peering  
fabrics are  beginning to emerge. As a result, the “edge” of the  
Internet is thickening, and that may be adding resilience to the  
network.

In Europe in particular, such connection points now route a  
significant part of the total traffic. AMS-IX is based in Amsterdam,  
where it is also run as a nonprofit neutral organization composed of  
344 members exchanging 775 gigabits of traffic per second.

“The rise of these highly connected data centers around the world is  
changing our model of the Internet,” said Jon M. Kleinberg, a computer  
scientist and network theorist at Cornell University. However, he  
added that the rise of giant distributed data centers built by Google,  
Amazon, Microsoft, IBM and others as part of the development of cloud  
computing services is increasing the part of the network that  
constitutes a so-called dark Internet, making it harder for  
researchers to build a complete model.

All of these changes have sparked a debate about the big picture. What  
does the Internet look like now? And is it stronger or weaker in terms  
of its resistance to failure because of random problems or actual  
attack.

Researchers have come up with a dizzying array of models to explain  
the consequences of the changing shape of the Internet. Some describe  
the interconnections of the underlying physical wires. Others analyze   
patterns of data flow. And still others look at abstract connections  
like Web page links that Google and other search engine companies  
analyze as part of the search process. Such models are of great  
interest to social scientists, who can watch how people connect with  
each other, and entrepreneurs, who can find new ways to profit from  
the Internet. They are also of increasing interest to government and  
law enforcement organizations trying to secure the Net and use it as a  
surveillance tool.

One of the first and most successful attempts to understand the  
overall shape of the Internet occurred a decade ago, when Albert- 
László Barabási and colleagues at the University of Notre Dame mapped  
part of the Internet and discovered what they called a scale-free  
network: connections were not random; instead, a small number of nodes  
had far more links than most.

They asserted that, in essence, the rich get richer. The more  
connected a node in a network is, the more likely it is to get new  
connections.

The consequences of such a model are that although the Internet is  
resistant to random failure because of its many connections and  
control points, it could be vulnerable to cyberwarfare or terrorism,  
because important points — where the connections are richest — could  
be successfully targeted.

Dr. Barabási said the evolution of the Internet has only strengthened  
his original scale-free model. “The Internet as we know it is pretty  
much vanishing, in the sense that much of the traffic is being routed  
through lots of new layers and applications, much of it wireless,”  
said Dr. Barabási, a physicist who is now the director of Northeastern  
University’s Center for Network Science. “Much of the traffic is  
shifting to providers who have large amounts of traffic, and that is  
exactly the characteristic of a scale-free distribution.”

In other words, the more the Internet changes, the more it stays the  
same, in terms of its overall shape, strengths and vulnerabilities.

Other researchers say changes in the Internet have been more  
fundamental. In 2005, and again last year, Walter Willinger, a  
mathematician at AT&T Labs, David Alderson, an operations research  
scientist at the Naval Post Graduate School in Monterey, Calif., and  
John C. Doyle, an electrical engineer at California Institute of  
Technology, criticized the scale-free model as an overly narrow  
interpretation of the nature of modern computer networks.

They argued that the mathematical description of a network as a graph  
of lines and nodes vastly oversimplifies the reality of the Internet.  
The real-world Internet, they said, is not a simple scale-free model.   
Instead, they offered an alternate description that they described as  
an H.O.T. network, or Highly optimized/Organized tolerance/Trade-offs.  
The Internet is an example of what they called “organized complexity.”  
Their model is meant to represent the trade-offs made by engineers who  
design networks by connecting computer routers. In such systems, both  
economic and technological trade-offs play an important role. The  
result is a “robust yet fragile” network that they said was far more  
resilient than the network described by Dr. Barabási and colleagues.

For example, they noted that Google has in recent years built its own  
global cloud of computers that is highly redundant and distributed  
around the world. This degree of separation means that Google is  
insulated to some extent from problems of the broader Internet. Dr.  
Alderson and Dr. Doyle said that another consequence of this private  
cloud was that even if Google were to fail, it would have little  
impact on the overall Internet. So, as the data flood has carved many  
new channels, the Internet has become stronger and more resistant to  
random failure and attack.

The scale-free theorists, Dr. Alderson said, are just not describing  
the real Internet. “What they’re measuring is not the physical  
network, its some virtual abstraction that’s on top of it,” he said.  
“What does the virtual connectivity tell you about the underlying  
physical vulnerability? My argument would be that it doesn’t tell you  
anything.”