Problem: Slow Transfer, Packet Losses, Congestion Avoidance, Shaping and Policing!
This is a response to a question asked on Tuesday 5th December by “u/thegreattriscuit” in Reddit’s “r/Networking” subreddit.
Question Summary - The problem was slow file transfer throughput across a long 1 Gbps WAN (“across an ocean”) and caused by packet losses. However, we’re told that the packet loss behaviour was consistent and readily reproducible for this particular iPerf test - but not apparent for other transfers across the same link.
The provided “topology” diagram is below. The flow is from Host-A at the left to Host-Z on the right and the packet losses occur somewhere between the two points (as indicated by the blue line between two capture points). The losses could be within the Cisco 4500, ASR1000, Force10 WAN, ASR1000 or Force10 switch).
A commercial packet analysis tool called NetData Pro was used to perform this analysis and provide the detrail visuals included -
Full Details of the analysis and Conclusions following -
*Note for larger diagrams click on image -