[lwip-users] question about lwIP performance

[Dmitri Snejko]

Hi,

I have done performance tests recently for  FreeRtos/Lwip   running  on 
MPC52259  eval board 80Mhz and  on my own LPC2468   72Mhz. Both boards 
show quite similar results . The test was netio  tcp network benchmark.
I have got  ~ 900kB/s  for receiving  and 1200kB/s for transmitting. 
Speed was lower for small packets (less then 1024 bytes).
The most sensitive lwipopts settings I found were:

TCP_WND
TCP_SND_BUF
MEM_SIZE
TCP_MSS

Also  I had big improvement when I set network frame buffers size equal 
to MTU. TCP_SND_BUF improves transmission speed  when it  is more then  
2 times of mss. Here are my optimal settings for lwipopts:

#define MEM_SIZE                6 * 1024

/* TCP receive window. */
#define TCP_WND                 3000
/* TCP Maximum segment size. */
#define TCP_MSS                 1460

/* TCP sender buffer space (bytes). */
#define TCP_SND_BUF             3000

Regards, Dmitri.


>Hi All,

>I use lwiP on GPRS channel. I just find the send/recieve is a bit slow 
with lwIP. I use the lwIP replace platform TCP/IP stac, and lwIP is much 
stable  in GPRS >environement.  but a little slow.
>
>I hard to make detailed debug on GPRS channel.  If there any known 
paramter could be adjusted to increase the send performance.
>
>Is there any check list for me to known where is the problems comes from?
>
>Sorry to i give imcomplete information.