Seems as if there's nobody who knows an answer to the question.
To get a step nearer to a solution I would be glad to know:
* if there is a restiriction how many connections a Flex - AIR client opens to the same host.
* and if there is a way to increase the maximum number of parallel connections
Sorry we haven't resolved this yet. I've forwarded your question along to our Webkit experts.
Hopefully this info helps.
On Windows we make use of the IE http stack for our internet connection. There is a registry setting available in the system to limit the i-connections in IE to two. Different behavior exists on Mac and Linux, but I don't believe the number of connections is kept to a minimum. Please see this post for more details.
To add to what Chris mentioned, AIR on Linux makes use of its own networking stack and at any point of time, does not allow more than two connections to the same server. Unfortunately, as of now there is no configuration setting to modify the same.
I am not sure if there exist a lot of use-cases for modifying the 'number of connections' value - however it would be great if you can log a bug for AIR on Linux for the same.