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KA9Q - A Cheap Intranet Solution

There is a software package which I had underestimated for a long time: KA9Q - an elegant way to turn an old 286 + modem + network card into an internet mail server. This is what we did at the DGD and, together with pegasus mail and the mercury gateway, such a hookup is well capable of linking LANs mailwise by a PPP Modem dialup line.

KA9Qs advantage over other network operating systems is its simplicity. It's so dumb that it does not try to do things you don't want to. For example, in contrast to other SMTP mailservers (e.g. sendmail) KA9Q does store messages for an arbitrary long time without trying at fixed intervals, but only when a "smtp kick [remote site]" command is issued, which can happen automatically when a PPP link comes up. This feature is necessary if you want to use a dial-up line (leased lines are very expensive in Germany) to poll email for an entire domain and not only for a bunch of individual POP3 accounts, which need to be set up one by one at the provider's host. KA9Q seems to be good enough, that (if I understood it right) Demon, a british internet provider, uses it at customer's sites for precisely this purpose.
When I asked a local internet provider about such a service, he said "we can't" and offered to install our KA9Q-server at their site and install a seperate phone line, so we could call it on demand...

At the DGD we used a 286/16 with KA9Q as the central mailserver for an entire group of subdomains (*@*.dgd.org). If you mailed me at my office email address before mid 1997 (when I switched to Linux), this went through the tiny little thing.

In the meatime I had to discover that KA9Q has limitations - it tends to crash (or lock up the phone line, which can be worse with german local phone charges of 3$ per hour) whenever a mail attachment of more than 300-1000 kB arrives. Every few month it needs a little bit of attention (and be it just to clean up the ever growing log file). This is tolerable at a site like an amateur radio station, where a knowledgeable administrator is present anyway, but not if it takes days before someone realizes the existence of an e-mail problem, several more days before it's being tracked down to be KA9Qs fault and another day or two before the administrator finds time to drive to the site. For this reason, most of the mail servers within the DGD are now running LINUX.

The low cost of hard- and software makes KA9Q an affordable technology. The special properties make KA9Q well suited for educational purposes - it can act like a standard internet server, without the complexity of a full blown unix system. Only recently it saved my day in a LAN environment where I had to transfer the Novell client software to a Windows 98 client that refused to recognize the file server with the Microsoft client. Just enter "start ftp" on the KA9Q mailer (286/16, 1 MB RAM, 30 MB HD) and you have a slow but functional way to transfer any file from one Windows 9x box to another, that works even when nothing else works.

KA9Q has been developed by radio amateurs ("KA9Q" is the callsign of Phil Karn, the original author), who use it as a full fledged TCP/IP-mailbox with mail forwarding, ftp server, telnet-bbs and IP-router. The air protocol is usually some kind of packet radio. With emphasis on the IP-router functionality, the same is done by universities in eastern Europe and some german people, who managed to connect by ISDN. The program, together with source code (C and Assembler) is available on simtel-mirrors (ftp and CDROM) or here - just the average seeker (who is not a radio amateur) won't look at the ham radio section...

All these users have some properties in common with missionaries, churches and third world users: little money and little hardware, but some technical understanding (or at least friends willing to help) and a lot of enthusiam, so it looks like a package suitable for this group of users.

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Last updated: 05.05.2007 17:42:59 Martin Stut, email: email address as image, Marburg, Germany
URL: http://www.stut.de/ka9q.htm