Van Jacobson is currently chief scientist at Packet Design LLC . Prior to that, he was Chief Scientist at Cisco Systems and group leader for the Network Research Group at Lawrence Berkeley Laboratory.
Jacobson is best known for his work in IP network performance and scaling; his work redesigning TCP/IP's flow control algorithms to better handle congestion is said to have saved the internet from collapsing due to traffic in 1988-1989. He is also well-known for the TCP/IP Header Compression protocol described in RFC1144, mainly meant to improve performance over low-speed links, popularly known as Van Jacobson TCP/IP Header Compression.
He has authored a few widely used network diagnostics tools, such as traceroute, pathchar and tcpdump.
Jacobson received the ACM SIGCOMM Award in 2001 for his work.