By Jim Kurose
MucH Has cHanGed in the 50 years
since the invention of packet switch-ing and the early network designs and
deployments that would evolve into today’s Internet. Network size has grown
from a number of nodes that could
be counted on our hands to a number
estimated to be upward of 800 million network-attached devices and an
equally large number of intermittently
connected mobile devices. We have
also witnessed the transition to commercial Internet use in the 1990s; the
creation of the World Wide Web, P2P
networks, Voice-over-IP, and streaming media services; and the increasing
importance of security and privacy.
And yet, amid this change, the Internet’s architecture and a number of the
key protocols that form its technical
foundation were conceived and subsequently standardized more than 30
years ago. Certainly, there have been
changes and improvements in the intervening years, but it’s remarkable indeed that the designs that began with
Cerf and Kahn’s original 1974 landmark paper1 have proven so durable in
the face of so much change—a tribute
to the prescience and wisdom of the Internet’s original designers.
While early computer networks
focused on “delivering data between
computers or between computers and
terminals,” 1 today’s Internet is argu-
ably more concerned with connecting
people with content and information.
Cisco’s Visual Networking Index not-
ed that P2P and video traffic together
account for nearly 80% of consumer
Internet traffic in 2011. In such a con-
tent-centric worldview, what a person
wants, rather than where it is located,
is what matters most; content, rather
than the server on which content re-
sides, becomes the starting point. A
number of the current networked ap-
plications, including content distri-
bution networks (CDNs), publication-
subscribe (pub/sub) systems, and P2P
file-sharing applications, are already
content-focused. But they do so as ap-
plications running on top of the Inter-
net and (importantly) there are many
separate CDNs, pub/sub systems, and
P2P file-sharing services.
1. Cerf, v. and kahn, r. a protocol for packet
network interconnection. IEEE Transactions on
Communications Technology 22, 5, 627–641.
2. Clark, d. the design philosophy of the darPa Internet
protocols. In Proceedings of 1988 ACM SIGCOMM
(stanford, Ca, aug. 1988), 102–111.
Jim Kurose ( firstname.lastname@example.org) is a distinguished
university Professor (and past chairman) in the
department of Computer science and executive associate
dean of the College of natural sciences at the university
of Massachusetts, amherst, Ma.