TCP Scaling Window resizing issue with Bulk send

[Parag Medhe]

Hi,

I am setting my SendBufSize and RecvBufSize for TCP to be 2^32 using Config::SetDefault before the BulkSendHelper is initialized. I expected to see certain  throughput but I am getting much lower. 

On digging deeper, I saw the TCP window scaling being set at the beginning of the connection to 2 and then not changing during the whole session. The TCP window scaling  is using the default buffer sizes (128K) and not the size that is provided by Config::SetDefault().

Could you please tell me the possible reason for such behavior? 

Thanks.

[Tommaso Pecorella]

Hi,

no idea, but please check if the issue is still there in ns-3-dev.

T.