Van Jacobson is probably best known for redesigning TCP/IP flow-control algorithms to more efficiently handle congestion in the late 80s. If you were otherwise busy (I was suffering through the 8th grade, myself), the Internet was on the verge of collapsing under traffic congestion. Some wanted to abandon the project; Jacobson was one of the very few who advocating saving it.

Jacobson began his career as an experimental physicist, developing control systems for the Department of Energy in the 1970s. He began his study of networks in the 1980s and spent 25 years as a researcher at the DOE-sponsored Lawrence Berkeley Laboratory's Information and Computing Science Division; he was a senior staff scientist heading the Network Research Group.

Jacobson was one of the three creators of MBone, launched in 1992, and the principal architect of its tools: one was 'whiteboard,' which Jacobson developed with Steve McCanne: it allows participants in an M-Bone session to write, type, and draw on a shared drawing window. Any image, e.g., computer-assisted designs or x-ray images, can be imported into the whiteboard window. Another was 'Lightweight Sessions,' a conference coordination tool that allows people to announce or sign up for an audio or video conference. MBone has shown around-the-clock coverage of space shuttle flights, provided an opportunity for doctors in England and Sweden to observe and question a surgeon in San Francisco performing a complex liver operation and a place for Ph.D. candidates to defend their dissertations to committee members.

In 1998, Jacobson took on the position of chief scientist at Cisco Systems, where he has worked on technologies such as QoS and Voice Services. Since the presentation of his seminal paper, Congestion Avoidance and Control, at SIGCOMM 88, Jacobson has written dozens of papers and RFCs concerning the performance and scaling of IP networks. He has contributed many of the tools currently used in the IP development community, including traceroute, pathchar, and tcpdump (the latter with Craig Leres and Steven McCanne, both of LBL). He is a co-author of multicast-based conferencing tools such as vic, vat, sd and wb, as well as the RTP and SDP standards.

For his long and distinguished career and many contributions to the field of data communications, Jacobson has been named the 2001 recipient of the ACM SIGCOMM Award.

He is currently chief scientist at privately-held Packet Design, founded in May 2000.

From Van Jacobson's abstract for his April 1997 MSRI talk:

Ten years ago the Internet was plagued with routing problems and I developed a tool called traceroute ( that allowed any user, anywhere on the Internet, to trace the path packets take and isolate routing loops and black holes. Today the Internet appears to be experiencing severe congestion problems. I've developed a new tool, pathchar (, that allows any user to find the bandwidth, delay, average queue and loss rate of every hop between any source & destination on the Internet. A surprisingly large amount of mathematics is required to do live analysis of a busy (and often broken) network path.


  • LBNL's Network Research Group
  • the tcpdump program
  • pathchar
  • MBone and Van Jacobson Tools
  • Multimedia conferencing over the Internet
  • a few RFCs that Jacobson authored or co-authored

  • RFC 1144: Compressing IP/UDP/RTP Headers for Low-Speed Serial Links
  • RFC 1185: TCP Extension for High-Speed Paths
  • RFC 1889: RTP: A Transport Protocol for Real-Time Applications
  • RFC 2327: SDP: Session Description Protocol.
  • You may also want to check out 'TCP/IP Research Papers' for Jacobson RFCs

    The man is busy, y'all. I'm just writing about him and need some vitamin C and a nap.

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