How reliable is PyAMF -- AS3 remoting?

Dear pyamf-list,

currently I'm working out an interactive shell. It's a little more elaborated than the shell-example provided by the pyamf project. My major concern is right now that occasionally messages are swallowed. This isn't a regular phenomemon and not easy to reproduce.

The basic setup is as follows. The OS is Windows XP. The Python version is 2.5. with pyamf-0.3.1. The application uses a NetConnection object and defines `onResult` and `onFault` methods passed into a `Responder` object. As as server I use the basic WSGI demo server from the "Hello World" example. It listenes to localhost. There are two service functions, `echo` and `interact`. It suffices to consider the simpler `echo` function because the phenomenon occurs there as well.

On each user input a `sendCommand`  method in the AS3 code is called and a callback of `onResult` is expected. A common sequence is

sendCommand
onResult
sendCommand
onResult
...

However occasionally onResult is not called and one obersves the following sequence

sendCommand
onResult
sendCommand
sendCommand
...

This is not an effect of the speed of user interaction. One can pause for a few seconds and the latter sequence is nevertheless observed.

I don't know where to start looking for a solution to this problem and which communication endpoint is to blame. Maybe someone here has some expertise and stumbled over comparable problems in the past?

I also consider a workaround implementing a communication protocol by which the message is sent to the client multiple times in increments of about 500ms until the server receives an ACK or a timeout / threshold ( e.g. 5 times ) otherwise. I'd like to avoid such workarounds if I can in particular they are only means to patch some behavior I do not fully understand.

Kind regards, Kay