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 Active Networks at UW
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 David Wetherall
 Andrew Whitaker
 Janos folk at Utah
 STP folk at Utah

We have a range of research in the area of active networks and more generally extensible distributed systems. Pointers to STP and ANTS, our main active network projects, are below. See also the Scriptroute page for an open Internet measurement facility that uses code-shipping and runs on Planet:Lab.

STP (Self-spreading Transport Protocols)

The main STP page is at Utah; please check there for up-to-date software and information.

STP is a system developed by the University of Washington and the University of Utah to support the rapid evolution of transport protocols. New transport protocols are written in a type-safe version of C and run in-kernel. STP-enabled end-hosts then exchange these untrusted transports when they wish to communicate with each other. This late binding of protocols to hosts removes many of the delays and constraints that are otherwise commonplace when upgrading the transport protocols deployed on the Internet. The key challenge in developing a practical system for transport evolution is to achieve a synthesis: dual-end upgrades must be sufficiently expressive to encode a large set of transport protocols including those yet to be invented, sufficiently low-level to achieve high levels of performance, and still sufficiently restricted so that they can be checked for a multitude of safety and security properties. Both the network at large and the two end hosts must be protected from ill effects.


  • TCP Meets Mobile Code
    Parveen Patel, Jay Lepreau, David Wetherall, Andrew Whitaker
    9th Workshop on Hot Topics in Operating Systems, May, 2003.

Last updated 11.11.2005 by djw.

ANTS (Active Node Transfer System)

ANTS is a Java-based toolkit that has been widely-used for experimenting with active networks. It provides a node runtime that can participate in an active network, and a protocol programming model that allows users to customize the forwarding of their packets.


See the Utah Flux ANTS EE page for the current status and material on their Java NodeOS. The latest distribution contained here is version 2.0.2, released on 12/7/1 (read the README ). Previous versions include 2.0 and 1.3.1

Some links to local documentation:



Earlier and classic papers are below. (See Wetherall's home page for a more complete list.)

Last updated 11.11.2005 by djw

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