Earlier this year I had the unique (to me) opportunity to serve as a technical expert witness in a court case in the UK. Tony’s already written about the case but I wanted to add my perspective.
I was contacted by Bird and Bird to see if I might be willing and able to act as a technical expert in a court case; that’s all they said at first. The nature of the questions they were asking soon clued me in that the case involved Exchange ActiveSync and multiple-point-of-presence (MPOP) support for presence publishing– two completely separate technologies which Motorola/Google had lumped together in this case. .
My role was to perform a wire-level analysis of the protocols in question: EAS, SIP/SIMPLE as implemented in Lync, and the Windows Live Messenger protocol. For each of these protocols, my job was to produce an accurate, annotated packet capture showing exactly what happened when multiple devices synchronized with the same account, and when the status on one device changed.
This isn’t what most people think of when they think of expert testimony; in courtroom dramas and books, it always seems like the expert is being asked to provide an opinion, or being cross-examined on the validity of their opinion. No one wanted my opinion in this case (which is perfectly normal), just for me to to accurately and impartially report what was happening on the wire.
This proved to be incredibly interesting from a technical standpoint. Like most administrators, it had never really occurred to me to look into the depths of the EAS protocol itself to see exactly what bits were being passed on the wire. After a great deal of study of the ActiveSync protocol documentation and many a late night slaving away over Wireshark and Network Monitor captures, I’d produced a report that showed the actual network traffic that passed between client(s) and server for a variety of test scenarios, along with an explanation of the contents of the packets and how they related to user action on the device.
Along the way, I gained a new appreciation for the economy of design of these protocols– it’s surprising how efficient they are when you look at them at such a low level. (And a shout out to Eric Lawrence for his incredibly useful Fiddler tool, which made it much easier for me to get the required data into a usable format.) I found a few bugs in Wireshark, learned more than I wanted to about SSL provisioning on Windows Phone 7.5 devices, and generally had a grand time. I particularly enjoyed working with the attorneys at Bird and Bird, who were quite sharp and had lovely accents to boot. (I’m not sure they enjoyed my accent quite as much, but oh well.)
When I finished my report, I submitted it to Bird and Bird and that was the last I heard of the case until today, when Mr. Justice Arnold issued his ruling. It was submitted as part of Microsoft’s justification explaining why their implementations did not infringe on Motorola’s patent; the purpose of having an annotated set of packet captures was to clearly illustrate the differences between the claimed innovations in the patent and Microsoft’s implementation to show why Microsoft wasn’t infringing.
Florian Mueller has a good summary of the case that highlights something I didn’t know: the patent at issue is the only one on which an Android manufacturer is currently enforcing an injunction against Apple. I am no patent attorney, but it would seem that Apple might have grounds to have this injunction lifted. It will be interesting to see what happens in the related German court cases that Muller cites, but it’s hard for this layman to see any other likely result besides a Microsoft win… but we will see.
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