Re: [lwip-users] [TCP raw API] Nagle + tcp_output interaction (behavior in 24 throughput tests)

[goldsimon]

vr roriz wrote:
>[..]
>Then, I added the send_now control option, letting tcp_output (with
>send_now = 0) to be called by lwip itself.

Ok, so the application *never* calls tcp_output() but you leave this completely 
to the stack? That might work somehow, but will lead to totally unpredictive 
performance, as you have measured.

Also, even if you don't call tcp_output(), that doesn't always ensure two 
segments get sent together. Trying to achieve something like that is just not 
what TCP is like. TCP is a streaming protocol, which is what people tend to not 
understand. You can try to work around its streaming nature and make it 
datagram like, but once you think you got it working like you want to, don't be 
surprised if it doesn't in the next version...

Simon