Radio Shortest Path First

RSPF is a specialised routing protocol that is used by amateur radio operators to work out how to shuffle packets around our complicated networks. There are many reasons why our networks are complicated, but one significant thing is that you can no longer assume that just because you hear one station, then they can hear you. This means you can have a lot of unidirectional routes. This is why standard protocols don't work very well over amateur packet radio.

Brief History

The current specification is RSPF version 2.2, written by Fred Goldstein K1IO. Until recently, if people were using RSPF at all, they would of been using RSPF version 2.1, which is available in the NOS program, written by Phil Karn and others. The RSPF code itself in NOS was written by Anders Klements.
Now with the knowledge of how his protocol worked in real life, Fred then updated and improved RSPF to version 2.2. And, until late 1995, that was all that happened.
What did happen was that I was in my senior years in my undergraduate degree at University of Technology, Sydney and looking for an interesting Thesis. After seeing emails from Carl Makin VK1KCM asking if anyone was going to fix RSPF in NOS, this gave me my idea for my Thesis.

Current versions of RSPFd

Soon after graduating, rspfd-0.04 was released for everyone to try. This was a package that provided a daemon on Linux that used RSPF v2.2. After many bug fixes and improvements, we are currently up to release 1.0.

Getting RSPFd

You can either get a stable version of rspfd from Source Forge Download Site or the development version from CVS (Note: the modulename is rspfd. There is also Debian, SuSE and RedHat packages.
Now there is talk of taking RSPF and making into a more generic protocol; not just for amateur radio networks but using the things we have learned from these networks and applying them to wireless networks in general. We'll wait and see how this turns out.

RSPF Resources

Below is some resources which you may find useful to get more information about rspf.

RSPF SourceForge Project Page
The Project page has a lot of information about the program itself, such as open bugs, current versions etc.

RSPF v2.2 Specification
This version of the specification has the same words as the original text version (see below) but is now hopefully a bit easier to read in its HTML format.

RSPF Specification (text)
This is the original place for the plain ASCII text version of the RSPF specification. There is also a HTMLied version by following the link below.

Section 5 of the HAM HOWTO
The HAM HOWTO is an excellent document for find out what is available for the radio amateur. Section 5 describes, amongst other things, the RSPF daemon.

Here is the most Frequently Asked Questions that I have received about RSPF and the RSPF daemon. Some of these questions and answers are ones I have put in believing that they will be asked. It is a good idea to check the FAQ first before asking a question, the answer may be there!

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Last Modified: Wed, 22 Nov 2000
Copyright © 2000 Craig Small