Subject:  HUBS AND SPOKES: A TeleGeography Internet Reader
<http://www.telegeography.com/Publications/hs00.html>

What does the Internet look like?  Most engineers draw it as a cloud. 
That shouldn't surprise anyone: in a sense, there is no Internet, only
networking standards like TCP (Transmission Control Protocol) and IP
(Internet Protocol) which allow an ever-increasing number of private
data networks across the world to exchange digital information.  These
networks and the traffic they carry give the Internet its form.  That
they interconnect gives the Internet its substance.

But if you look inside the Internet cloud, a fairly distinct
hub-and-spoke structure begins to emerge at both an operational
(networking) and physical (geopolitical) level.  A well-known Internet
graph created at Lucent Technologies by Bill Cheswick and Hal Burch, for
example, is built up from thousands and thousands of nodes (routers) and
edges (links between routers), each reflecting a possible path from
Cheswick and Burch's home network to the rest of the Internet.  Even a
casual review of these hubs and spokes can provide a rough idea of the
Internet's scale and some of its major constituents
<http://www.peacockmaps.com>.

What about the geopolitical dimensions of this hub-and-spoke model?
Traditionally, the Internet's basic transmission facilities have been
centered around the U.S., the hub whose backbone spokes connected the
rest of the world.  Some spokes were quite thick, like those linking the
U.K., Canada and Japan.  Others were pencil thin: Russia's and Brazil's,
for example.  This was no conspiracy.  The topology, largely unplanned,
reflected the Internet's U.S. origin; its embryonic commercial
structure, including America's head start in building network backbones;
its status as home to most Internet content; and waning monopoly pricing
of cross-border data links outside the U.S.

By 1999, this U.S.-centric structure had slowly begun to shift. Today
more bandwidth links key European cities to each other than to the U.S.,
making western Europe the first hub to emerge from North America's
shadow. Intra-regional links between Asian networks are also growing. 
As a result, the Internet's global hub-and-spoke structure has begun to
diffuse, replicating itself within regions. In Europe, for example,
single cities have begun to play the role that the U.S. once did
worldwide.

Yet country-by-country numbers tell only part of the story.  More
detailed data for metropolitan areas suggest that the emerging structure
of the Internet's hub-and-spoke structure is based upon a core of meshed
connectivity between world cities on coastal shores -- Silicon Valley,
New York, and Washington, DC; London, Paris, Amsterdam, and Frankfurt;
Tokyo and Seoul.

The Internet's architecture is still evolving.  *Hubs and Spokes*, the
first publication from TeleGeography's Internet program, expands and
updates our past material to help readers understand that evolution. 
Like our PSTN (public switched telephone network) research, our Internet
work focuses on international industry structure, network topology, and
traffic flow.

As the Internet takes its place at the core of an emerging public
network, hard questions are coming up.  What shape is that network
taking on -- and will those who operate it be organized horizontally, by
function, or vertically, by end-to-end slice?  How will those players
interoperate, both technically and financially, to ensure that the hubs
and spokes continue to connect?  Who will govern the cloud, and what are
the demand drivers causing it to expand?

PRIMER

Architecture:  How is the global Internet structured?  Not long ago, the
answer seemed easy: the Internet was U.S.-centric.  As regional hubbing
makes geographical diversity a more pervasive network feature, Net
architecture moves beyond its U.S.-domestic and
global-but-still-U.S.-centric phases toward a third stage characterized
by a distributed global presence.  That is the theory, anyway.  But a
combination of regulatory and economic factors have threatened to
forestall the end of the U.S.-centric phase.  Where do things stand? 
And where are they headed?

Finance:  Who pays for the Internet?  The answer is complicated: a
typical Internet transmission may involve many different networks --
five, say, or fifteen -- and is broken up into many different packets,
which may take radically different paths to get from point a to point b.
 That makes it hard to bill Internet communications in the way that
traditional phone communications are billed.  How do peering and transit
models for traffic exchange fit in -- and what happens in practice?

Governance: Who governs the Internet?  Most Netizens would once have
scoffed at the question, and probably sent unfriendly e-mails to the
person posing it.  But dramatic growth has transformed the Internet into
both a quasi-public global infrastructure and a very big business.  In
doing so, its priorities have shifted toward stability and
predictability.  That's where governance comes in.  What's up with
ICANN?  And how did we get there?

Demand: Demand growth for IP capacity is almost impossible to state:
because IP applications tend to grab the bandwidth they need -- slowing
down rather than halting when less is available -- and because faster
performance impacts user behavior directly, new capacity is filled
readily, and the challenge for many backbone providers is simply to
build as fast as possible.  Keeping this challenge in mind, we look to
the network's edges and why they're being populated by an increasing
number of users; the on-ramps that let them get data to and from the
core; and the content, devices, and interactive applications which are
helping increase the volumes involved.

Voice: One of the Internet's most-discussed demand drivers is voice
telephony.  During the last year, voice-over-IP (VoIP) players have
attracted very large amounts of new capital, and the trend toward telco
investments in VoIP carriers could well accelerate the long-awaited
convergence between the telco and IP worlds.  How does VoIP work?  And
where does it stand?

INTERNATIONAL INTERNET BANDWIDTH

Providers: A market overview and comprehensive list of more than 250
international Internet service providers (IISPs) headquartered in 85
countries provides a guide -- and direct coordinates -- for the online
maps and data which will help readers size up the players.

Connectivity and Exchanges: How much international Internet bandwidth
goes where?  A guide to international city-to-city bandwidth provides a
geographical summary of the global Internet, along with a table of the
top 50 international Internet hub cities worldwide.  Maps help present
the information visually, showing international backbone routes for the
Europe, Asia/Pacific, and Americas regions.  And the world's Internet
exchange points -- facilities where network traffic is traded -- are
indicated, with pointers to over 200 facilities in 76 countries (see
http://www.telegeography.com/ix).

INTERNATIONAL INTERNET INDICATORS

A guide to the other metrics used to size the Internet's global growth,
including country-by-country Internet user counts; the spread of
different languages on the Internet; and the nature of links between
sites in one country and another.  Pointers to pertinent projects are
provided, and a geographical twist on the tried-and-true host counts is
included. Reference pages provide easy access to Internet and telephony
country codes, and include a "bit primer" to match bandwidth
technologies with their speeds.