IOhannes,
I tried your version of tcpserver/client and it unfortunately shows no improvement in our performance tests (16 wirelessly networked machines) with latency spikes sometimes as high as 1-2 seconds. In addition, your iteration of tcpserver/client suffers from the bugs that were fixed in Martin's version, namely misreporting number of connected clients, crashes, xruns when broadcasting, and stale sockets following the crash.
Could it be that this has something to do with how Pd deals with networking or are these externals completely independent from Pd's threading (given that they spawn their own threads pretty much or everything)?
Alternately, this may be simply the issue of cheap wireless cards built into our netbooks and/or driver issues.
Best wishes,
Ico