[ns] The average Jitter calculated in Iperf

[Tiago Junqueira]

 Hi,
  Sorry this is not a specific ns post, but if someone knows:)
  In the RFC 1889 the instantaneous jitter is given by:
J=J+(|(Rj-Sj)-(Ri-Si)|-J)/16
     I'm running a simulator and i have the packets sent and received
time. The problem is that i don't know how iperf gives the final
result, so i can't do the same and compare the real results with the
simulator results.

while iterating, if i do:
Jsum=J+Jsum, and then J_average=Jsum/(num_packets-1) the results
wouldn't be the same as iperf because  in a extract:

tiago at ksat67:~$ iperf -c 192.168.101.11 -u -b 500k -t 30
[  3]  0.0-10.0 sec    479 KBytes    393 Kbits/sec  9.184 ms    0/  334 (0%)
[  3] 10.0-20.0 sec    471 KBytes    386 Kbits/sec  11.203 ms   83/  411 (20%)
[  3] 20.0-30.0 sec    468 KBytes    383 Kbits/sec  10.314 ms   99/  425 (23%)
[  3]  0.0-32.5 sec  1.50 MBytes    388 Kbits/sec  11.123 ms  205/ 1277 (16%)

the value 11.123 ms is not the average of the another 3 above.

 thanks advance, Tiago Junqueira
Student