A CONVERSATION WITH VAN JACOBSON

Photography by Steve Skoll

Making the case for content-centric networking

To those with even a passing interest in the history of the Internet and TCP/IP networking, Van Jacobson will be a familiar name. During his 25 years at Lawrence Berkeley National Laboratory and subsequent leadership positions at Cisco Systems and Packet Design, Jacobson has helped invent and develop some of the key technologies on which the Internet is based. He is most well known for his pioneering contributions to the TCP/IP networking stack, his seminal work on alleviating congestion on the Internet, his leadership in developing the MBone (multicast backbone), and his development of several widely used IP networking tools, such as trace-route, pathchar, and tcpdump.

Now a Research Fellow at PARC (Palo Alto Research Center), Jacobson continues to do groundbreaking work. His latest work on CCN (content-centric networking) took the networking community by storm when his seminal 2006 talk, “A New Way to Look at Networking,” was released on the Web as a Google Tech Talk (http://video. google.com/videoplay?docid=-6972678839686672840&ei =iUx3SajYAZPiqQLwjIS7BQ&q=tech+talks+van+jacobson).

For our interview this month, we enlisted another networking heavyweight, Craig Partridge, chief scientist for networking research at BBN Technologies, to speak with Jacobson about CCN and what it means for the future of the Internet. Partridge is an ACM Fellow, a former chair of ACM SIGCOMM, and was once editor-in-chief of ACM SIGCOMM Computer Communication Review. Jacobson and

Partridge first met in 1987 when they were both working on TCP-related problems and have been periodically bouncing research ideas off each other ever since. We are immensely grateful for their participation and hope that their discussion helps to enlighten software engineers about this exciting new direction for networking technology.

 

CRAIG PARTRIDGE In a paragraph or two, can you describe the gist of what content-centric networking is to somebody who knows a little bit about how the Internet works? What does CCN do to that model? VAN JACOBSON The easiest place to start is the history.

The networking that we use today grew out of work in the 1960s and 1970s. At that time, the problem that people wanted to solve was what we call a resource-sharing problem today. You had one computer that had a tape drive and another that didn’t, or one computer that had a printer and another that didn’t.

There were not all that many computers, and they were big and expensive. Everything that was attached to them was big and expensive, and it was a really interesting problem to be able to share this big, expensive gear among computers. The model that drove the networking development was, “Can we extend the I/O bus so that we can share these resources between machines?”