I have created 4 tcp ports (server in listening mode) and trasfers data received to UARTS and viseversa. i.e. Ethernet to Serial converter (4 port).
I works well for few hours but later it stops working. lwipopts defines are as follows:
/* ---------- Memory options ---------- */
/* MEM_ALIGNMENT: should be set to the alignment of the CPU for which
lwIP is compiled. 4 byte alignment -> define MEM_ALIGNMENT to 4, 2
byte alignment -> define MEM_ALIGNMENT to 2. */
#define MEM_ALIGNMENT 4
/* 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. */
#define MEM_SIZE (10*1024)
/* 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. */
#define MEMP_NUM_PBUF 64 //100
/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
per active UDP "connection". */
#define MEMP_NUM_UDP_PCB 6
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
connections. */
#define MEMP_NUM_TCP_PCB 10
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
connections. */
#define MEMP_NUM_TCP_PCB_LISTEN 10 //6
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
segments. */
#define MEMP_NUM_TCP_SEG 20
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
timeouts. */
#define MEMP_NUM_SYS_TIMEOUT 10
/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */
#define PBUF_POOL_SIZE 12
/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */
#define PBUF_POOL_BUFSIZE 512
Mohsin Madki.