10.1 Agent state

The C++ Agent../ns-2/agent.h includes enough internal state to assign various fields to a simulated packet before it is sent. This state includes the following:

addr _	node address of myself (source address in packets)
dst _	where I am sending packets to
size _	packet size in bytes (placed into the common packet header)
type _	type of packet (in the common header, see packet.h)
fid _	the IP flow identifier (formerly class in ns-1)
prio _	the IP priority field
flags _	packet flags (similar to ns-1)
defttl _	default IP ttl value

These variables may be modified by any class derived from Agent, although not all of them may be needed by any particular agent.