Re: [lwip-users] lwIP performance

[yueyue papa]

after IO delay is adjusted,

the FTP upload speed is up to 600k byte/s.
the FTP download speed is up to 300k byte/s

The download will cause TCP ZERO windows information happen. I am not clear about it. If this happen, the download speed will lost heavily.

I attached my download Trace.pcap.

################# parts of lwipopt.h#############

/* Controls if TCP should queue segments that arrive out of
   order. Define to 0 if your device is low on memory. */
#define TCP_QUEUE_OOSEQ         0  

/* TCP Maximum segment size. */
#define TCP_MSS                 1460 

/* TCP sender buffer space (bytes). */
#define TCP_SND_BUF             (TCP_MSS*4) 

/* TCP sender buffer space (pbufs). This must be at least = 2 *
   TCP_SND_BUF/TCP_MSS for things to work. */
#define TCP_SND_QUEUELEN       (4 * TCP_SND_BUF/TCP_MSS)

/* TCP writable space (bytes). This must be less than or equal
   to TCP_SND_BUF. It is the amount of space which must be
   available in the tcp snd_buf for select to return writable */
#define TCP_SNDLOWAT           (TCP_SND_BUF/2)

/* TCP receive window. */
#define TCP_WND                (TCP_MSS * 4) 

/* Maximum number of retransmissions of data segments. */
#define TCP_MAXRTX              8

/* Maximum number of retransmissions of SYN segments. */
#define TCP_SYNMAXRTX           8
#################


############# my pool ###########
LWIP_MALLOC_MEMPOOL(64, 64)
LWIP_MALLOC_MEMPOOL(16, 128)
LWIP_MALLOC_MEMPOOL(8, 1104)
LWIP_MALLOC_MEMPOOL(20, 1536)
###############################

Is there configuration problem in my setup?

Why my download is only half of my upload?  

Lee

On Thu, Feb 4, 2010 at 10:56 PM, Kieran Mansley <address@hidden> wrote:

On Thu, 2010-02-04 at 09:40 -0500, Bill Auerbach wrote:
> Maybe I’m wrong, but MBS is MegaBytes/Sec and MbS is MegaBits/Sec.
> KBS is KiloBytes/Sec and KbS is KiloBits/Sec.

I'd stick a "/" or a "p" in there too:

Mbps = Mb/s = Mega bits per second
MBps = MB/s = Mega bytes per second
and so on.

> So you want 200KBS which is about 1600KbS, which is 1.6MbS.  If I’ve
> got the math and numbers right here, then 200KBS this should not be a
> problem at all.

That's the performance he's getting, he wants to know if that is good or
bad and so whether he should spend time making it better.

Kieran



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downloadTrace.pcap
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