Strange results from Statistics

Hi,

I need to have a graph for bandwith usage while the client uses a webapp. I captured all packets from the client to the proxy (on the proxy).

But the graph in IO Graph show much more traffic for the one client as the router, between all clients and the proxy, for the whole net.

Then I tried to get the usage per second from tshark

tshark.exe -nr "<File>"  -z "io,stat,1,ip.dst==client&&ip.src==proxy"

But the result is strange too. I often have very huge numbers at the end which can't be true. For example:

=======================================================  
| IO Statistics                                       |  
|                                                     |  
| Interval size: 1 secs                               |  
| Col 1: Frames and bytes                             |  
|     2: ip.dst==client&&ip.src==proxy                |  
|-----------------------------------------------------|  
|              |1                 |2                | |  
| Interval     | Frames |  Bytes  | Frames |  Bytes | |  
|---------------------------------------------------| |  
...  
| 138  4 <> 1385 |    0 |       0 |    0 | 64848607 | |  
| 1385 <> 1386 |     27 |   24532 |    0 | 64848607 | |  
| 1386 <> 1387 |    450 |  425266 |    0 | 64848607 | |  
| 1387 <> 1388 |    891 |  836781 |    0 | 64848607 | |  
| 1388 <> 1389 |    234 |  227972 |    0 | 64848607 | |  
| 1389 <> 1390 |    261 |  253114 |    0 | 64848607 | |  
| 1390 <> 1391 |   1588 | 1514653 |    0 | 64848607 | |  
| 1391 <> 1391 |    170 |  163242 |    0 | 13248269094487389 | |  
=======================================================

Also, why there is an amount of 0 Frames but still a value for Bytes?

The client used only the webapp while capture.

My goal is to see the peaks for traffic. The average usage I got from Summary already.

Thanks in advance.