[lwip-users] [lwip] lwIP (current) : large data transfers seem to break lwIP

[Chris Borrelli]

Probing for help...

I am seeing an interesting problem when sending large chunks of data 
from lwIP.  After about 2 1/2 MB of data gets sent to the remote host, 
lwip just stops sending data...

I have a callback setup (sent) that gets called every time new tx buffer 
space becomes available.  I think this happens whenever lwIP receives an 
ACK for previously transmitted data.  Inside the callback I call 
tcp_write with remaining data to send.  After ~2.5 MB of data is sent 
out, the callback doesn't get called ever again.  I suspect this number 
is related to my lwipopts.h settings.

Ethereal shows that all the data that is sent from lwIP is ACK'd by the 
remote host, and still the stack seems to just die.

Has anyone run into this or anything similar before?  

Setup:
cvs version of lwIP running on a PPC405 (300MHz).
tcp_fasttmr called every 2 mS
tcp_slowmr called every 5 ms
Ethernet uses interrupts on rx side.

 -Chris

my lwipopts.h:
- - - - - - - - - - - - - - - - - - - - -
#ifndef __LWIPOPTS_H__
#define __LWIPOPTS_H__

#define NO_SYS 1
#define LWIP_CALLBACK_API 1

#define MEM_ALIGNMENT           4
#define MEM_SIZE                8 * 1024 * 1024
#define MEMP_NUM_PBUF           64
#define MEMP_NUM_UDP_PCB        1
#define MEMP_NUM_TCP_PCB        8
#define MEMP_NUM_TCP_PCB_LISTEN 16
#define MEMP_NUM_TCP_SEG        255

#define MEMP_NUM_NETBUF         0
#define MEMP_NUM_NETCONN        0
#define MEMP_NUM_API_MSG        0
#define MEMP_NUM_TCPIP_MSG      0
#define MEMP_NUM_SYS_TIMEOUT    0

#define PBUF_POOL_SIZE          512
#define PBUF_POOL_BUFSIZE       1536

#define PBUF_LINK_HLEN          16

#define LWIP_TCP                1
#define TCP_TTL                 255
#define TCP_QUEUE_OOSEQ         1
#define TCP_MSS                 1476
#define TCP_SND_BUF             512 * 1024
#define TCP_SND_QUEUELEN        2 * TCP_SND_BUF/TCP_MSS
#define TCP_WND                 16 * 1024
#define TCP_MAXRTX              12

#define ARP_TABLE_SIZE 4

#define IP_FORWARD              0
#define IP_OPTIONS              1
#define ICMP_TTL                255

#define LWIP_DHCP               0
#define DHCP_DOES_ARP_CHECK     1

#define LWIP_UDP                0
#define UDP_TTL                 255

#endif /* __LWIPOPTS_H__ */


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