DnsCache and UDP Ports

I am setting up DNSCACHE to service a web crawler.

I've made the software changes (MAX_UDP) to DNSCACHE to
allow more simultaneous connections to exist but I believe I need to
do the same thing on the system front.

Question:

Is there a system setting that sets the maximum concurrent
UDP connections per application and/or total connections
system wide. Specifically DNSCACHE - Port 53.

-or-

Is there a DEFINE in the kernel source requiring a rebuild?
If so what module does it exist in?

Thanks in Advance...
Ed