The Internet today has several characteristics that are contrary to the
original design and intent, and more importantly, contrary to a effective,
robust and democratic allocation of resources. The ability of the
dynamically reroute traffic around points of failure was one of the earliest
features (made to survive nuclear war, as the saying goes), and is still
as extremely valuable.
In reality, though, dynamic rerouting requires a highly interconnected,
redundant network, and due to market conditions, this is not an accurate
description of the Internet today, especially not on local and regional
levels. On these levels, the network topology closely resembles several
trees, where an end user is connected to a provider, who is in turn
to an upstream provider, and so on for a few levels. Interconnection and
redundancy rarely happens, other than on the very highest level, where large
ISPs/backbone providers have peering agreements to exchange traffic, and in
interconnection points such as MAE East and West in the US, and
national-level exchanges in Europe. Since only large ISPs can enter into
peering agreements, this effectively controls and monopolizes the backbones.
The direct and most noticable result for end users is the extremely high
of hops and latency to get to hosts that reside on other backbone providers'
networks. The situation in Mexico City, my current place of residence, is an
excellent example. There are three or four large backbone providers
Mexico City, and all of them maintain separate fiber lines to the US.
no national level peering agreements, so if you want to reach a host
street that happens to be on a different provider's network, your
to Texas and back.
Federico gives me the following example:
On more than one occasion, I have tried to get my mail. It is hosted on the
Ximian servers, in Cambridge. I am in Mexico City. For some reason the
(apparently only) route to that machine is being unusably slow, and
my mail just stalls. So I ssh to one of the gnu.org machines, hosted in
downtown Boston. Physically there are not more than 5 kilometers
Ximian box and the GNU box. My connection to it is reasonably fast most
time; fortunately this is the case this time as well. Copying my mail from
ximian.com to gnu.org is really fast. And copying it from gnu.org to
am in Mexico City, somewhere inside unam.mx, takes a reasonably small
time, i.e. no more than what it would take from ximian.com on a good network
day. This is ridiculous. The Ximian and the GNU boxes are practically
each other physically, and yet the routes from UNAM in Mexico City are
extremely different performance- and reliability-wise. If the network
a lame tree, things would be fine and redundant and happy.
Additionally, this makes the entire network infrastructure extremely
to failure. Basically, you can consider yourself singly connected to the
world. Any piece of hardware in your upstream is a potential single point of
failure, making the failure frequency rise exponentially with the number of
Available technology that might solve the problem
There are several low-cost, fairly long range point to point wireless
networking solutions available. All are line of sight, using directional
antennas, and cost in the range of 600-1500 USD per end (possibly less for
homebrew solutions using, for instance, amplified wavelan). The range is
typically 3-10 kilometers, and the bandwidth is in the low megabits
These devices are perfectly suited to setting up a network across a fairly
large metropolitan area, literally from rooftop to rooftop. It's
achieve critical mass, which suggests high population density in the
be preferable. We believe we have a perfect testing ground available: Mexico
City. With its 22 millon (low estimate) people, booming economy, and
by 60 kilometers of mostly flat ground, it should have more than enough
potential participants within radio range of any point in the city to
easy to reach critical mass quickly.
Such a network could be densely interconnected, with each node connected
least three others, and thus allowing dynamic rerouting around faults and
efficient bandwidth sharing.
The practical and social implications
Urbone aims to replace profit-driven, singly connected, ineffective network
structures with collaborative, non-profit, redundant ones, in which all
are connected to several of their nearest neighbours. This has advantages
both on the social, economical and technical level.
On the social level, this sort of structure encourages cooperation,
and sharing of duties between entities on the network. As the network grows,
the participants will take advantage of the possibilities of unhindered
dataflow to and from the other participants, hopefully helping to
work processes and streamline the way people work and cooperate, making
information disseminate wider and more quickly. This would make an excellent
incentive for a company to recruit its providers and customers as
in the network. A good example is ad agencies, newspapers, and
houses, which often send large amounts of data back and forth between them,
currently often on removable media, by courier. There are doubtlessly
groups of entities who would benefit from speedy digital data interchange in
the same way. The lower price also enables more egalitarian access to the
network, wiring individuals and organizations that were previously unable to
afford high-speed access.
On the economical level, the utility of the network grows exponentially with
the number of nodes, and the cost per participant decreases accordingly. A
network that's maintained by a non-profit entity will be able to
commercial provider both on price and availability. Everyone pays the same
price for the same service, and the network as an entity can buy
several external providers, sharing the cost equally.
On the technical level, the network will be massively interconnected,
facilitating on the fly rerouting to avoid network congestion and
bottlenecks. In an egalitarian, non-profit network, the traffic can flow
it's most effective, utilizing the network optimally, without regard for who
paid for that particular piece of pipe, or who's paying for the bandwidth
used. Additionally, the network will be extremely fault-tolerant, and will
allow a fairly large proportion of the nodes to go offline without splitting
the graph in two.
When the Urbone grows to a certain size, there are a number of possibilities
we'd like to look at pursuing. They vary in difficulty, desirability and
plausibility, but all of them are practically possible.
Voice over IP
As VoIP becomes more plausible, it would be natural for the Urbone to also
carry voice traffic between the nodes. This would allow the participants to
place free, high-quality phone calls to other participants. The Urbone could
also potentially be hooked up to a phone switch and collaboratively rent a
number of outgoing phone lines at bulk prices, allowing participants to cut
If the Urbone reaches a certain (rather large) size, streaming media
network would be quite possible and desirable. Since the gateways on the
network are centrally controlled, it would be one of the first places it
be possible to deploy IP multicast outside of an experimental setting. One
possible use would be for "Urbone Radio" or "Urbone TV", although
possible. High-quality sound only requires a fraction of the bandwidth on a
given link, and with multicast, the traffic could reach all interested nodes
while using a minimum of bandwidth.
Mobile networking/ubiquitous access
Given an even geographical distribution of Urbone nodes, it would be quite
plausible to outfit each one with a transciever for non-line of sight mobile
networking, along the lines of wavelan. This would allow any Urbone
to register his wavelan card's MAC address centrally, and have access to
wireless networking almost anywhere in the Urbone area. This could be
or without roaming support (roaming being somewhat more tricky to implement,
although Mobile IP is a fairly simple standard, especially if one actually
controls the nodes of the network). This would make ubiquitious, low-cost
wireless networking a reality for a wide range of portable devices, from
laptops to handhelds. At the very minimum, this would allow you to bring a
laptop anywhere in the Urbone coverage area, run pump, and go to work,
regardless of whether or not you're in a park, a café, visiting a
friend, or in your home or office.
Mobile Voice over IP
Given the implementation of both VoIP and mobile IP in the Urbone network, a
natural continuation would be to cobine the two, turning every portable
into a potential cellphone equivalent.
We're hoping that if the Urbone becomes successful in our initial deployment
area, people will start similar efforts in other cities. As the citywide
networks grow, it would be natural to start considering possibilities for
interconnecting them. Depending on geographical distance, several
exist (for relatively short ranges, there's microwave, for longer distances,
Extending Urbone to cover non-urban areas is a distinct possibility. Mexico,
for instance, has a vast number of small villages which are sadly
underpriviledged when it comes to communication infrastructure (and mostly
everything else). The Red Escolar project aims to equip all Mexican schools
with computer labs of older computers running free operating systems.
connections from school to school across the country would make a perfect
compliment to this effort. Corporate efforts to sponsor schools are
very popular in Mexico, with entities such as the Coca-Cola Company donating
large amounts to schools. It seems plausible to get similar corporate
to sponsor network access for poor communities.
Each node would have a small router (probably a small Intel PC running
and radio links to at least two other nodes. It should regularly broadcast
network status information, such as link saturation and latency, to allow
rerouting of traffic to utilize the network optimally. Exactly what protocol
would be used to transmit this information and the corresponding routing
configuration information is an open question at the moment. Both
routing and network information protocols like BGP and SNMP, as well as more
high-level solutions with custom protocols (over TCP/IP) would be possible
options. We're looking for feedback from people more knowledgable about
than us who can advise us on what the best strategy would be. It's essential
that the routers be possible to upgrade and reconfigure remotely.
It could be useful for the nodes to run very modern networking
as IPv6. After all, when deploying a completely homogenous network where
there's complete control of the standards, it would be a shame to not
the progress made since IPv4 was finalized. Cryptography (IPSec) might be
particularly useful, given that the data itself is easily interceptable.
Optionally, each node could also run miscellaneous high-level services to
lighten the load on the networking infrastructure, such as web caches,
DNS servers, etc. It would presumably be fairly trivial to tune standard
software to function optimally in a network where each node requests the
information from its nearest neighbour. This could also dramatically
load on the network's connections to the world.
The embryonic Urbone wouldn't require more than one connection to the world,
although two or perhaps three would be ideal. We presume that once the
reaches a certain size, ISPs, particularly smaller ones, would see the
of hooking up to the network and allocate some of their own connections
world to Urbone traffic, since it would result in a net reduction in
connections they actually pay for. In this way, Urbone will also
function as an
ad-hoc interchange between Mexico City ISPs, reducing the amount of traffic
that has to go to the US and back.
What would it cost? Well, if each point is connected to three others,
cost will be a couple of thousand dollars, plus the router/server box, for a
total of about 3000 dollars per node. This is a high estimate, it might be
possible to bring it as far down as half of that, or even lower.
2 Mbps connectivity costs about 5000 dollars/month in Mexico today (possibly
less), in addition to installation costs. 512kbps is about half that price,
with upgrades from 512kpbs to 2Mbps being very cheap. It seems clear
network doesn't need many nodes before the cost becomes substantially lower
than what any telco can offer. At about 10-15 nodes, the savings become
extreme, at about 100 nodes they become negligible for companies and
institutional users, and at about 200 it gets interesting to compete with
dialup internet access for single users, by wiring up every apartment
with a node. Beyond that, well, that's when it starts getting really
Competing with telcos is interesting from a social and philosophical
perspective. Communications companies are transnational entities,
created by a
long series of mega-mergers, in which the commercial interests
infrastructure intermingles with similar commercial interests producing the
content. Many people, including myself, find this to be a reason for
concern. It's a socially correct thing to offer up a grassroots
infrastructure near-monopolies, much like the free software movement has
a grassroots alternative to the software giants who seemed poised to
monopolize the market just five to ten years ago.
In the interest of thinking big, it would not be impossible to envision
digital wireless network covering and interconnecting large urban areas
completely in 5-10 years, all financed and built by the users, in an
egalitarian, fair manner, delivering data networking, voice, broadcast
and other services.
Where we are, and where we're going
We're currently very early in this process. We're trying to map out our
for technologies and structures to use, preparing for an initial
a handful of nodes some time in the first half of 2001. We're looking for
people with knowledge in a wide range of networking-related fields to
discussion at the Urbone
list. Areas of knowledge that are relevant include wireless and general
networking (theory and/or practice), routing, IPv6, Mobile IP, and related
areas. We'd love to hear general comments about the concept here on
and to take detailed technical discussion to the mailing list.