[ns] trace record discrepancies and format explanation.

[Devendra Goyal <goyald@email.uc.edu>]

- 0.0001 17 20 cbr 1500 ------- 0 17.0 19.17 0 17
+ 0.0001 18 20 cbr 1500 ------- 0 18.0 19.18 0 18
- 0.0001 18 20 cbr 1500 ------- 0 18.0 19.18 0 18
r 0.001415 20 19 cbr 1500 ------- 0 18.0 19.18 0 18
r 0.00264 20 19 cbr 1500 ------- 0 0.0 19.0 0 0
r 0.003865 20 19 cbr 1500 ------- 0 1.0 19.1 0 1

+ 0.004476 6 20 cbr 1500 ------- 0 6.0 19.6 1 22
+ 0.004528 14 20 cbr 1500 ------- 0 14.0 19.14 1 23
h 0.005052 1 20 cbr 1500 ------- 0 1.0 19.1 1 24
r 0.00509 20 19 cbr 1500 ------- 0 0.0 19.0 0 0
+ 0.005152 1 20 cbr 1500 ------- 0 1.0 19.1 1 24
h 0.005752 5 20 cbr 1500 ------- 0 5.0 19.5 1 25

Above are two sections of same trace file from an Ethernet LAN simulation
using CBR with UDP as traffic generator.
Following problems, somebody please explain:
* Packet with seq no. 0 is being received two times. Why?
* Where does the 4th field 20 comes from? I have only 20 nodes from 0 to
19 and all the traffic is going from first 10 nodes to last 19th node.
* 2nd and 3rd fields after the flag, say first one 17.0 and 19.17. What
this "." notation stands for?

Thanks a lot.

DEV