Yep, a [netsend] should do the trick. There's heaps of network goodness in Cocoa so you should find something to pick up your packets. Stick to UDP for simplicity.
http://developer.apple.com/reference/Cocoa/idxNetworking-date.html
But these are mostly abstract classes for URLS, services and cookies fwict
You want a simple socket in your Paradiddle gizmo,
I don't know Paradiddle , maybe there's what you need there already, called something like NetSocket
All things indicate you want something thats a wrapper to a BSD socket.
Discusses
http://lists.apple.com/archives/cocoa-dev/2005/Jan/msg01696.html
Source of simple non forking server you could hack in
http://www.oreillynet.com/pub/a/mac/2002/12/26/cocoa.html?page=3&x-maxdepth=0