[maxmsp] OSC Buffer size, Packets Per Second

I am sending a constant stream of OSC messages via UDP inside a DIY Pluggo Plugin.

I am sending them back to myself, 127.0.0.1, localhost.

I am sending 45 packets per second and it works fine.

When I have more than one instance of the plug in though, I am getting network congestion.

So I was wondering if anyone could tell me:

a)How many packets I could realistically hope to send per second.

b)How to set up the udp buffer to maximize the above figure.

If anyone knows the answer, thanks alot

Gavin