Maximum count of parallel VNC connections

[Chris]

Hi all,
maybe someone of you can help with his knowledge.
On version 2.1.2 of qemu I could open up 100 concurrent VNC connections 
to one qemu running VM without problems.
But with version 2.12 somehow I'm not able to open more than 32 
connections at the same time. On the 33rd connection I just get the 
string "RFB 003.008" but then the connection hangs.
I tried to find out what changed by diffing those versions in git but I 
did not find anything (whether in the commit log nor in the code 
changes) that lead me to the new connection limit.

Does anyone know how I can extend this limit, or where I find the 
limitation in the code? Mybe this limit is not directly found in qemu. 
But if I start a regular vncserver, I don't have any limit.
Thanks very much in advance for any help on this problem.
Best regards, -chris-