[lwip-users] Re: retransmission every 9 pacakets.

[Yang]

    for the retransmission problem I had post before,
I had found some sources of it now. It happend every 9 packets
because I set the MEM_SIZE  in opt.h  to 1024*10 ,
and lwip run out of memory every 9 packets. Now I set  MEM_SIZE 
to 1024*32, memory error didn't happened anymore.
     But retransmission is still there, every 29 packets.
It seem that the macro
 #define TCP_SND_BUF    1024*60 
#define TCP_SNDLOWAT    TCP_SND_BUF/2
is the reasion while it was 29, if I set it to 1024*32 ,
retrans will hapend every 15 packets.it was 60/2-1(and 32/2-1)
I can see the SND_BUF was filled up and in lwip_stats.
    I think set TCP_SND_BUF bigger then MEM_SIZE is not a good 
idea, but the test gave me fastest performance.(for TCP_SND_BUF=1024*60,
1032k/s, TCP_SND_BUF=1024*32, 800k/s) 
   I attach part of my opt.h here ,please help me get thing right. Thx!
 ##########################################################################
#ifndef MEM_ALIGNMENT
#define MEM_ALIGNMENT                   4
#endif

/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high. */
#ifndef MEM_SIZE
#define MEM_SIZE                        1024*32//1600
#endif

#ifndef MEMP_SANITY_CHECK
#define MEMP_SANITY_CHECK       0
#endif

/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
   sends a lot of data out of ROM (or other static memory), this
   should be set high. */
#ifndef MEMP_NUM_PBUF
#define MEMP_NUM_PBUF                  32//16
#endif

/* Number of raw connection PCBs */
#ifndef MEMP_NUM_RAW_PCB
#define MEMP_NUM_RAW_PCB                4
#endif

/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
   per active UDP "connection". */
#ifndef MEMP_NUM_UDP_PCB
#define MEMP_NUM_UDP_PCB                4
#endif
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB
#define MEMP_NUM_TCP_PCB                5
#endif
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
   connections. */
#ifndef MEMP_NUM_TCP_PCB_LISTEN
#define MEMP_NUM_TCP_PCB_LISTEN         8
#endif
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
   segments. */
#ifndef MEMP_NUM_TCP_SEG
#define MEMP_NUM_TCP_SEG                32//16
#endif
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
   timeouts. */
#ifndef MEMP_NUM_SYS_TIMEOUT
#define MEMP_NUM_SYS_TIMEOUT            8///3
#endif

/* The following four are used only with the sequential API and can be
   set to 0 if the application only will use the raw API. */
/* MEMP_NUM_NETBUF: the number of struct netbufs. */
#ifndef MEMP_NUM_NETBUF
#define MEMP_NUM_NETBUF                 32///2
#endif
/* MEMP_NUM_NETCONN: the number of struct netconns. */
#ifndef MEMP_NUM_NETCONN
#define MEMP_NUM_NETCONN                4
#endif
/* MEMP_NUM_APIMSG: the number of struct api_msg, used for
   communication between the TCP/IP stack and the sequential
   programs. */
#ifndef MEMP_NUM_API_MSG
#define MEMP_NUM_API_MSG                32//8
#endif
/* MEMP_NUM_TCPIPMSG: the number of struct tcpip_msg, which is used
   for sequential API communication and incoming packets. Used in
   src/api/tcpip.c. */
#ifndef MEMP_NUM_TCPIP_MSG
#define MEMP_NUM_TCPIP_MSG              16//8
#endif

/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */

#ifndef PBUF_POOL_SIZE
#define PBUF_POOL_SIZE                  32//16
#endif

/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */

#ifndef PBUF_POOL_BUFSIZE
#define PBUF_POOL_BUFSIZE               2000//128
#endif

/* PBUF_LINK_HLEN: the number of bytes that should be allocated for a
   link level header. Defaults to 14 for Ethernet. */

#ifndef PBUF_LINK_HLEN
#define PBUF_LINK_HLEN                  16//14
#endif

/* ---------- ARP options ---------- */

/** Number of active hardware address, IP address pairs cached */
#ifndef ARP_TABLE_SIZE
#define ARP_TABLE_SIZE                  10
#endif

/**
 * If enabled, outgoing packets are queued during hardware address
 * resolution.
 *
 * This feature has not stabilized yet. Single-packet queueing is
 * believed to be stable, multi-packet queueing is believed to
 * clash with the TCP segment queueing.
 * 
 * As multi-packet-queueing is currently disabled, enabling this
 * _should_ work, but we need your testing feedback on lwip-users.
 *
 */
#ifndef ARP_QUEUEING
#define ARP_QUEUEING                    1
#endif

/* This option is deprecated */
#ifdef ETHARP_QUEUE_FIRST
#error ETHARP_QUEUE_FIRST option is deprecated. Remove it from your lwipopts.h.
#endif

/* This option is removed to comply with the ARP standard */
#ifdef ETHARP_ALWAYS_INSERT
#error ETHARP_ALWAYS_INSERT option is deprecated. Remove it from your 
lwipopts.h.
#endif

/* ---------- IP options ---------- */
/* Define IP_FORWARD to 1 if you wish to have the ability to forward
   IP packets across network interfaces. If you are going to run lwIP
   on a device with only one network interface, define this to 0. */
#ifndef IP_FORWARD
#define IP_FORWARD                      0
#endif

/* If defined to 1, IP options are allowed (but not parsed). If
   defined to 0, all packets with IP options are dropped. */
#ifndef IP_OPTIONS
#define IP_OPTIONS                      1
#endif

/** IP reassembly and segmentation. Even if they both deal with IP
 *  fragments, note that these are orthogonal, one dealing with incoming
 *  packets, the other with outgoing packets
 */

/** Reassemble incoming fragmented IP packets */
#ifndef IP_REASSEMBLY
#define IP_REASSEMBLY                   1
#endif

/** Fragment outgoing IP packets if their size exceeds MTU */
#ifndef IP_FRAG
#define IP_FRAG                        0// 1
#endif

/* ---------- ICMP options ---------- */

#ifndef ICMP_TTL
#define ICMP_TTL                        255
#endif

/* ---------- RAW options ---------- */

#ifndef LWIP_RAW
#define LWIP_RAW                      0 // 1
#endif

#ifndef RAW_TTL
#define RAW_TTL                        255
#endif

/* ---------- DHCP options ---------- */
#ifndef LWIP_DHCP
#define LWIP_DHCP                       0
#endif

/* 1 if you want to do an ARP check on the offered address
   (recommended). */
#ifndef DHCP_DOES_ARP_CHECK
#define DHCP_DOES_ARP_CHECK             1
#endif

/* ---------- UDP options ---------- */
#ifndef LWIP_UDP
#define LWIP_UDP                        1
#endif

#ifndef UDP_TTL
#define UDP_TTL                         255
#endif

/* ---------- TCP options ---------- */
#ifndef LWIP_TCP
#define LWIP_TCP                        1
#endif

#ifndef TCP_TTL
#define TCP_TTL                         255
#endif

#ifndef TCP_WND
#define TCP_WND                         1024*10//2048
#endif 

#ifndef TCP_MAXRTX
#define TCP_MAXRTX                      12
#endif

#ifndef TCP_SYNMAXRTX
#define TCP_SYNMAXRTX                   6
#endif


/* Controls if TCP should queue segments that arrive out of
   order. Define to 0 if your device is low on memory. */
#ifndef TCP_QUEUE_OOSEQ
#define TCP_QUEUE_OOSEQ                 0////1
#endif

/* TCP Maximum segment size. */
#ifndef TCP_MSS
#define TCP_MSS                         1500//128 /* A *very* conservative 
default. */
#endif

/* TCP sender buffer space (bytes). */
#ifndef TCP_SND_BUF
#define TCP_SND_BUF                     1024*60//256 //1024*16
#endif

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


/* Maximum number of retransmissions of data segments. */

/* Maximum number of retransmissions of SYN segments. */

/* 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 */
#ifndef TCP_SNDLOWAT
#define TCP_SNDLOWAT                    TCP_SND_BUF/2
#endif
###############################################################
                                 
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡Yang
address@hidden
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2007-09-25