[lwip-users] Tuning the Segment-/Packet-/Framerate of lwIP-Stack

[Kolpak, Maximilian (ext)]

Hello,

 

I´m using lwIP-Stack to send 8Byte-Commands from a Embedded System to a PC-Workstation.

Since I don´t want the Stack to concatenate multiple Commands in one segment I deaktivated

that in the tcp_output.c (in tcp_enqueue(...)):

 

/* If there is room in the last pbuf on the unsent queue, chain the first pbuf on the queue together with that. */

if (0 && useg != NULL && // @ - MK - 04.07.06 - No concatenation

TCP_TCPLEN(useg) != 0 &&

!(TCPH_FLAGS(useg->tcphdr) & (TCP_SYN | TCP_FIN)) &&

!(flags & (TCP_SYN | TCP_FIN)) &&

/* fit within max seg size */

useg->len + queue->len <= pcb->mss)

 

I ran a few Performance Tests and found out, that when a frame has actualy been sent, the stack seems to wait ~170ms before

the next frame can be sent. I think it waits for more data to fill the segment.

 

My question is how can I "tune" the stack, that it doesn´t wait that long for more data, before it actually sends the frame?

 

Thanks a lot,

 

Max