[FoRK] The Next Internet? Inside PARC’s Vision of Content Centric Networking

Eugen Leitl eugen at leitl.org
Wed Aug 8 03:42:02 PDT 2012


The Next Internet? Inside PARC’s Vision of Content Centric Networking

Wade Roush8/7/12Follow @wroush	

Van Jacobson	

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The Internet may be hurtling toward collapse under the strain of too much
traffic. But PARC research fellow Van Jacobson thinks he knows how to fix it.

He’s done it before. Back in the mid-1980s, when the Internet was seeing its
first modest surge in usage, Jacobson noticed that data packets were piling
up on the message routers of the day, like cars waiting for cross-traffic to
clear before entering an intersection. Working with fellow Berkeley computer
science instructor Mike Karels, he came up with a small change to the
Transmission Control Protocol (TCP) that, in essence, allowed packets to ease
into the intersections gradually, curing the congestion. Later, Jacobson also
came up with a way to compress the “headers” or address sections of Internet
Protocol (IP) packets from 40 bytes down to about 3 or 4 bytes, which made a
big difference at a time when so many packets were still squeezing through
narrow telephone lines.

But the challenges the Internet is facing today are very different, and call
for a much broader solution, Jacobson believes. He argues that the global
computing network was never designed to carry exabytes of video, voice, and
image data to consumers’ homes and mobile devices, as it’s now doing, and
that it will never be possible to increase wireless or land-line bandwidth
fast enough to keep up with demand. In fact, he thinks the Internet has
outgrown its original underpinnings as a network built on physical addresses,
and that it’s time to put aside TCP/IP and start over with a completely novel
approach to naming, storing, and moving data.

Jacobson’s alternative is called Content Centric Networking, or CCN, and it’s
grown into the single biggest internal project at PARC, the Xerox-owned
research center that’s famous as the birthplace of graphical computing, laser
printing, and the Ethernet standard. If the ideas behind CCN were broadly
adopted, PARC researchers believe, it would speed the delivery of content and
vastly reduce the load on the networking equipment at the Internet’s core.

It would also pose a challenge to the model of utility-style storage and
processing that’s come to be known as cloud computing. And that might
undermine many current business models in the software and digital content
industries—while at the same time creating new ones. In other words, it’s
just the kind of revolutionary idea that has remade Silicon Valley at least
four times since the 1960s. And this time, PARC doesn’t want to miss out on
the rewards.

“When there is widespread adoption of CCN there will be lots of opportunities
to build valuable businesses on top of it that are really impossible to
foresee today,” says Teresa Lunt, vice president of PARC’s Computing Science
Laboratory. “The main reason we’re investing is because we’re in love with
the technology, and we want CCN to make it out into the world…[but] we know
that PARC will be able to participate in the upside as well.”

Replacing “Where Is It?” with “Who Wants It?”

To understand why Content Centric Networking is so different, you have to
start by looking at today’s Internet, which was designed back in the days
when there were only a handful of machines that needed to talk to each other,
and the network was used mainly for short bursts of point-to-point
communication. In this established scheme, every piece of content has a name,
but to find it you have to know in advance where it’s stored—which means the
whole system is built around host identifiers and file hierarchies like
www.xconomy.com/san-francisco/2012/08/07/the-next-internet/. (The first part
of that URL gets translated into the IP address, which leads to
the server at St. Louis, MO-based Contegix where Xconomy’s content database
is hosted. The rest refers to the sub-sub-sub-folder on that server where
WordPress, our content management system, stored this page.)

The fundamental idea behind Content Centric Networking is that to retrieve a
piece of data, you should only have to care about what you want, not where
it’s stored. Rather than transmitting a request for a specific file on a
specific server, a CCN-based browser or device would simply broadcast its
interest in that file, and the nearest machine with an authentic copy would
respond. File names in a CCN world look superficially similar to URLs (for
example, /parc.com/van/can/417.vcf/v3/s0/Ox3fdc96a4…) but the data in a name
is used to establish the file’s authenticity and provenance, not to indicate

It’s easy to see how much sense this makes compared to the current
client-server model. Say I’m using my Apple TV box to browse my Flickr photo
collection on my big-screen TV. To get each photo, the Apple TV has to
connect to Flickr, which is hosted on some remote data center owned by
Yahoo—it could be in Utah or North Carolina, for all I know. The request has
to travel from the Apple TV over my Wi-Fi network, into Comcast’s servers,
then across the Internet core, and finally to Yahoo. Then the photos, which
amount to several megabytes each, have to travel all the way back through the
network to my TV.

But the photos on Flickr are just copies of the originals, which are stored
on my camera and on my laptop, about 15 feet away from my TV. It would be
much smarter and more economical if the Apple TV could simply ask for each
photo by name—that is, if it could broadcast its interest in the photo to the
network. My laptop could respond, and I could keep browsing without the
requests or the data ever leaving my apartment. (In Jacobson’s scheme, file
names can include encrypted sections that bar users without the proper keys
from retrieving them, meaning that security and rights management are built
into the address system from the start.)

“The simplest explanation is that you replace the concept of the IP address
as the defining entity in the network with the name of the content,” says
Lunt. “Now all the talk in the network is about ‘Have you seen this content?’
and ‘Who needs this content?’ as opposed to ‘What is the routing path to
particular terminus in the network?’ It’s a simple idea, but it makes a lot
of things possible.”

For example, now that memory is so much cheaper than when the Internet was
first built, it’s becoming more economical to cache popular content at many
places throughout the network. This minimizes the distance content has to
travel to reach end users, and hence the amount of bandwidth consumed. Lunt
uses a real-world analogy. “It used to be that if you had a store and you
needed a product, you called up the factory for delivery and they sent a
truck,” she explains. “That model works for a small business in one town, but
it doesn’t scale up to a nationwide or global network. So people have built
warehouses where you can cache a lot of stuff, and then people order from the
nearest warehouse. You can have a very efficient system without having to go
back to the factory for each order.”

Similarly, in a content-centric network, if you want to watch a video, you
don’t have to go all the way back to the source, Lunt says. “I only have to
go as far as the nearest router that has cached the content, which might be
somebody in the neighborhood or somebody near me on an airplane or maybe my
husband’s iPad.”

Of course, caching data at different points in the network is exactly what
content distribution networks (CDNs) like Akamai do for their high-end
corporate clients, so that Internet videos will start playing faster, for
example. But in a content-centric world, Lunt says, the whole Internet would
be a CDN. “Caching becomes part of the model as opposed to something you have
to glue onto the side.”

Tinkering with Applications

Computer scientists have been discussing the idea of name-based (as opposed
to location-based) networking since the 1970s. But the proposal began to pick
up steam in 2006. That’s when Jacobson, who’d done stints as head of the
Network Research group at Lawrence Berkeley National Laboratory and as chief
scientist at Cisco Systems and Packet Design, joined PARC to lead a new
Content Centric Networking research program.

PARC had been operating as a contract R&D lab—independent of Xerox, but
wholly owned by it—-since 2002. Its business model is to build internal
intellectual property and expertise, often with the help of government
funding and university collaborators, and then to get the technologies to
market through spinoffs or commercialization agreements with industry
partners. In 2006, for example, PARC licensed some of its natural language
search technology to a spinoff called Powerset, which was acquired by
Microsoft in 2008 for $100 million.

In 2009, after three years of design work, Jacobson’s team released CCNx, an
open-source software implementation of the protocols needed to build
research-stage content centric networks. The next year they released an
Android version of CCNx, optimized to run on smartphones, and joined the
Named Data Networking (NDN) initiative, a network of 11 university labs that
won $8 million in National Science Foundation funding for further development
of the CCN idea.

It’s unlikely any of that could have happened if Jacobson had tried to
develop his ideas inside a company like Cisco or Packet Design. “Having
worked at both large companies and startups, I came to PARC to make Content
Centric Networking a reality,” Jacobson said in a 2010 statement. The lab
“understands the importance of openness and collaboration to achieve success
for new network architectures,” he said.

In that vein, PARC hosted the first meeting of the Emerging Networks
Consortium this spring. It’s a group of big companies like Alcatel-Lucent,
BT, France Telecom-Orange, Huawei, Panasonic, and Samsung who want to
experiment with CCN technologies and have agreed to share what they’re
learning. “That has been a good validation for us that it’s not just us or
the academic sector” who are interested in CCN, says Jatinder Singh, PARC’s
director of mobile innovation strategy. “A lot of these industries are
actively tinkering with use cases they might want to implement.”

What might those cases be? To be clear, no one is talking yet about replacing
the existing Internet with a content-centric system. That would be
impractical, not to mention expensive. (And in practice, a new networking
standard would probably be implemented as an “overlay” on the existing
TCP/IP-based Internet, just as the Internet started out as an overlay on the
telephone network.) Rather, Lunt and Singh say the CCN approach is likely to
turn up first in specific applications on the edges of the network. Then, if
it’s successful enough, it might filter back toward the center.

The world of wireless medical devices is one area PARC is eyeing. The
traditional TCP/IP-based approach would be to equip these devices to connect
to the Internet via Wi-Fi; collect their data on a centralized server; then
retrieve the data from PCs or smartphones. But that comes with privacy and
security hazards—and there are no common standards yet for formatting or
exchanging medical data. “The medical device ecosystem is sort of
fragmented,” says Singh. “You have vendors producing blood pressure monitors
and scales and glucose meters, but so far there isn’t a clear mechanism for
aggregating data across those devices.”

On top of that, it’s overkill to send health data up to cloud servers if it’s
only needed within the confines of a single home or clinic. Imagine, instead,
that your CCN-equipped smartphone is constantly polling your scale, your
sleep monitor, and all your other home health devices for new data. Then when
you visit your doctor, the office network pulls the stored data directly from
your phone. “Using smartphones as hubs, we are looking at how CCN can allow
data to be gathered, contextualized, and shared in a secure fashion,” says

Members of the Emerging Network Consortium also have some very different
applications in mind, including using CCN-based networks to ease the burden
on cellular networks. That could work either by using CCN-based networks for
“backhaul” of data between wireless towers, or by offloading mobile data from
3G and 4G networks onto CCN-based Wi-Fi networks. “Voice over CCN” is another
possibility, as are lighting and environmental control systems for buildings
and home media sharing—pairing TVs, PCs, tablets, and smartphones with one
another without the need for a central Wi-Fi hub.

Twitter Without Twitter, Facebook Without Facebook

If it all sounds very speculative, that’s because it is. At this stage,
companies like Samsung may be investigating CCN mainly as a hedge against
uncertainty. “The technology industry is so fast-paced that they know that
whatever their cash cow is this year, in five to 10 years it’s going to be
something else,” says Lunt. “They have to be constantly looking for the next
big thing … Samsung makes equipment for carriers, they make handsets, they
make consumer devices. CCN could mean a whole new set of businesses for

But Content Centric Networking could also mean a whole new set of challenges
for companies in the content business. Apple, Amazon, Microsoft, Facebook,
Google, Twitter, Netflix, and their ilk have spent hundreds of billions of
dollars building siloed, centralized, proprietary storage and distribution
infrastructures, designed wholly around the client-server model and often
reachable only via tollbooths like the iTunes Store or Xbox Live. (See my
colleague Greg Huang’s recent take on the Four Horsemen of the Consumer

In a CCN world, consumers would probably still have to look at ads and pay
for movies, music, books, apps, and the like, but they might not be so
dependent upon a few giant cloud operators.

“One of the things that’s intriguing about not having to go to the source is
that you could start to think about implementing applications differently,”
Lunt says. “You could build apps that don’t have any notion of a server at
all. So you could have Twitter without Twitter or Facebook without
Facebook—that is, without having to have a major investment in hosting
content, because the network is caching it all over the place.”

Such architectures might give users more control over privacy and security of
their data, and let them share their own data across devices without having
to go through proprietary services like Apple’s iCloud, PARC executives say.

“What Apple is trying to do with iCloud is to say: You shouldn’t have to care
which device you got an app on, or which device you took a photo on, whether
it was your iPad or iPhone or MacBook Air. You just want your content to be
on the other devices when you want it,” says Steve Hoover, CEO of PARC. “That
validates our vision. But the way they are solving that puts more load on the
network than it needs to, and it requires consumer lock-in. So Apple may be a
user of this [CCN] technology one day, because it will make it easier. On the
other hand, they could also hate it, because it will make it a lot easier for
other people to provide that capability of getting the content whenever you

Already, there’s at least one startup, Cambridge, MA- and New York-based
Silver Lining Systems, that says it’s using concepts from Content Centric
Networking to solve performance problems in data centers and virtualized
computing environments. (The company includes former Verizon, Netezza, and
Endeca executives, according to the Boston Globe. It isn’t working directly
with PARC.) The CCN initiative could eventually lead to PARC spinoffs as
well, though nothing formal is in the works. “There could be a B2C play, an
Akamai for consumers,” Hoover speculates. “Right now, for example, I have
photos on Photobucket, Shutterfly, and Flickr, and I have to think about
where those photos are before I can go get them. Somebody could build a CCN
layer that interfaces with every photo-sharing service out there, and every
time you upload a photo, they manage that for you.”

How much might consumers be willing to pay for such a service? It’s hard to
know until someone builds it. Hoover says PARC’s job is to help companies
move in that direction.

“When Bob Metcalfe sat in this building and drew Ethernet on a paper napkin,
there wasn’t even an Internet, so nobody could have predicted that the
business model [for the Internet] was going to be Google search and
advertising,” Hoover says. “We can sit here and speculate about where the
tollbooths will go, but to me, it’s more about whether there are pockets of
money out there ready to address problems that people have now. The
tollbooths will go where they need to be.”

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