[ns]Urgent Questions on simulation

[Shen Ren]

Hi, All,
	I want to know where do ll and mac get initialed. What I am
doing is try to find a pointer to the mac object. Are they automatically
attached to the node when I called "$ns_ set node_(0) [new node]"???

	And when I create a node, how would ns know it is indeed a
mobilenode?

	The third question is when I call $udp start, what does udp
agent do? And if the udp agent does not get attached with an application
agent, what would it do after received a packet?

Thanks.

Shen Ren