argue why the slow transfer is slow
Hello Friends, My task is to find out why one trace is slow.
slow --> https://www.cloudshark.org/captures/5... fast ---> https://www.cloudshark.org/captures/0...
Both the capture is made near the server via TAPs.
From my findings the slow transfer is slow because of the nature of the application. The application sends some data to sever and the server only answers after resumption of this application data. Both the traces have the same pattern of packet flow in the sense that the server waits still the client sends some data. As the RTT of the slow transfer is high the total duration is longer. Can anyone find some other reason for this?
I could calculate the slow transfer took 12 seconds as there are 253 packets send by the client which took the time equal or grater than to RTT which is 2530ms. There are 2 packets sent after the re transmission time out which is took 2734 ms. Thus the network time spend by the slow transfer is 5264ms. The time which the server took till the capture point is not taken into account. Did i miss something?
Cool case. Could you please add some details regarding network environment? Server packets TTL is 59, how close to the server are you? What App type is it? Looking on PSH flags I see the server is sending a set of different-size objects/responses.
Two gaps in "slow transfer" are very interesting (packets 230, 513 areas). For me these look like TCP-related gaps (TCP packet train tail drop?). Retransmission timer of 1,5 sec isn't normal too, is it something between TAP and the server?