help: way of a packet through ns

Hi,

I have an Application that I'm trying to understand. I'm
using ns2.29.3 and have a scenario with mobile nodes and
ad-hoc routing. I'm trying to understand the ns2 packet
flow.

To send data, the Application calls

"agent_->sendmsg(MSG_BYTES_,data_->copy())"

I assume that this calls the attached UDPAgent. There I find
the procedure sendmsg() which has the line

"target_->recv(p)"

in it. What is that "target_"? Is it the routing
agent? Is it true that the routing agent has to call 

"target_->recv(p)"

again if it's an outgoing packet and

"dmux_->recv(p)"

if it's incoming?

Thank you a lot for your help.

Best,

-Matt