Latency, TCP ACKs and upload needs

Mikael Abrahamsson swmike at
Wed Apr 20 15:51:44 UTC 2016

On Tue, 19 Apr 2016, Jean-Francois Mezei wrote:

> Considering a single download TCP connection. I am aware that modern TCP 
> stacks will rationalize ACKs and send 1 ACK for every x packets 
> received, thus reducing upload bandwidth requirements. Is this basically 
> widespread and assumed that everyone has that ?

Typically you'll see one ACK per 2 packets, so you need approximately 1:50 
bytes up/down ratio for the ACKs.

It's possible to have middle boxes suppress some ACKs, please see thread 

Mikael Abrahamsson    email: swmike at

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