I don't know for certain cos I've never tried it. But I can't see any reason why the example given at http://www.alhem.net/project/example9/index.html can't be extended as follows:
	UdpTestSocket s1(h), s2(h);
	port_t port1 = 1300, port2=1400;

	s1.Bind(port1, 10);
	s2.Bind(port2, 10);
The only thing that could go wrong with this - aside from it not being supported - is that you might need two SocketHandlers:
	SocketHandler h1,h2;
	UdpTestSocket s1(h1), s2(h2);