Intermittent AirPort connectivity issues are among the toughest to troubleshoot at a service depot. I would say that in 90% of cases, the problem is with the actual network(s), but how can you spot the remaining 10%? Typically the machine will connect just fine to your local network. What you need is to generate some traffic and then monitor that over a period of time.

This is where iperf comes in:

Iperf was developed by NLANR/DAST as a modern alternative for measuring maximum TCP and UDP bandwidth performance. Iperf allows the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, datagram loss.

In other words it can do a hell of a lot more than just generate traffic, but that's what we'll use it for this time. iperf consists of two parts - a client and a server. I run our server on our FreeBSD box:

$ cd /usr/ports/net/iperf
$ sudo make install clean
$ iperf -sD

That installed iperf and launched it as a server in the background. Now we need to run the client on the machine we want to test. For this, I created a dead-simple AppleScript wrapper for iperf (which also includes the iperf binary itself), just double-click and enter the address of the iperf server. This launches iperf with some options apropriate for long term testing, in a new Terminal window.

The script (called "aptest", also part of MTK) tries to bind the iperf instance to the AirPort interface. This will wreak havoc on your wireless network - I would advise to set up a separate base station for this kind of testing. :-)

It would be fun to one day create a proper GUI that would plot the CSV output of iperf, but this will have to do for now...

BatchDMG is a handy utility for times when you have to image large collections of disks (like installation media etc). Just run it (as root, to avoid an authentication dialog) and start feeding your machine with media.

The imaging starts automatically when a volume is mounted. Should also work with multiple DVD drives. The images are bzip compressed (UDBZ, need 10.4 or later to open) and are named after the volume name. It ejects the media once the imaging has completed.

Should work with 10.5 or later (uses PyObjC).

WriteRoom

About 6 years ago, a customer brought a PowerBook 100 in for repairs. She was a writer and when I asked why she was still using (and spending good money on fixing) that ancient Mac when she could easily buy a new one. She replied that she's much more productive on the old one because there are no distractions. That the limitations of the machine and software actually help the user to do one thing really well...

This really stuck with me and now years later, trying to scribble things down, I'm feeling that same thing more than ever. Then I thought - why hasn't anyone made a text editor that would run in full screen? Well, luckily, they have.

rtorrent

When you get poor download speeds over BitTorrent you usually think it's because of lack of peers, misconfigured firewalls or throttled upload speeds - a crummy BT client is somewhere at the end of the checklist. Yesterday I discovered that a proper client can make all the difference in the world.

Same metafile, ~60k/s max download with BitTornado 0.3.8, 112k/s max with Transmission 1.0.1, 460k/s with rtorrent. I couldn't believe my eyes when I saw the difference and had to check my router stats which were consistent with the rate reported by rtorrent.

curses-only interface, available throught fink or macports.

GLTerm

I was fishing around for a full-screen Terminal app (distractions, remember...) and ran across GLTerm. Not only can it be used in fullscreen, but it also does an amazing impression of those old computer terminals I was never allowed to touch as a kid. :-)

Too bad only the Classic renderer seems to work on Leopard. :-/