Re: [lwip-users] Duplicate ACK problem with LWIP 1.3.2

[Hafiz Bashir]

On 06/01/2010 21:42, Hafiz Bashir wrote:
> On 06/01/2010 16:46, address@hidden wrote:
> > Hafiz Bashir wrote:
> > > Any help would be greatly appricated.
> > Since we do not know anything about the internals of your application 
> > and haven't seen the problem yet, you should try to debug, starting 
> > with enabling debug output for TCP by adding these lines in your 
> > lwipopts.h:
> >
> > #define LWIP_DEBUG
> > #define TCP_DEBUG                  LWIP_DBG_OFF
> > #define TCP_INPUT_DEBUG            LWIP_DBG_OFF
> > #define TCP_OUTPUT_DEBUG           LWIP_DBG_OFF
> > #define TCP_RTO_DEBUG              LWIP_DBG_OFF
> > #define TCP_CWND_DEBUG             LWIP_DBG_OFF
> > #define TCP_WND_DEBUG              LWIP_DBG_OFF
> > #define TCP_FR_DEBUG               LWIP_DBG_OFF
> > #define TCP_QLEN_DEBUG             LWIP_DBG_OFF
> > #define TCP_RST_DEBUG              LWIP_DBG_OFF
> >
> > You should then see debug output which you might be able to relate to 
> > the wireshark log and see at which point duplicate ACKs are sent.
> >
> > Simon
> I have attached the debug log from the application and the wireshark 
> capture file. Here is a snippet of the debug showing duplicate ACK's 
> being sent ?
>
> State: ESTABLISHED
>
> tcp_recved: recveived 1460 bytes, wnd 2920 (14600).
>
> TCP header:
> +-------------------------------+
> |       80      |     4099      | (src port, dest port)
>
> +-------------------------------+
> |           3649346719          | (seq no)
>
> +-------------------------------+
> |           0000006617          | (ack no)
>
> +-------------------------------+
> |  5 |   |011000|     64240     | (hdrlen, flags (
> PSH
> ACK
>
>
> ), win)
> +-------------------------------+
> |    0x79e4     |         0     | (chksum, urgp)
>
> +-------------------------------+
> +-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags
> PSH
> ACK
>
>
> -+-+-+-+-+-+-+-+-+-+-+-+-+-+
> State: ESTABLISHED
>
> tcp_receive: window update 64240
>
> tcp_receive: pcb->rttest 0 rtseq 6521 ackno 6617
>
> tcp_output: nothing to send (0x0)
>
> tcp_output: snd_wnd 64240, cwnd 4380, wnd 4380, seg == NULL, ack 6617
>
> State: ESTABLISHED
>
> tcp_recved: recveived 1460 bytes, wnd 2920 (14600).
>
> tcp_output: sending ACK for 3649348179
>
> tcp_recved: recveived 1460 bytes, wnd 4380 (13140).
>
> tcp_recved: recveived 1460 bytes, wnd 5840 (11680).
>
> tcp_recved: recveived 1460 bytes, wnd 7300 (10220).
>
> tcp_output: sending ACK for 3649348179
>
> tcp_recved: recveived 1460 bytes, wnd 8760 (8760).
>
> tcp_recved: recveived 1460 bytes, wnd 10220 (7300).
>
> tcp_recved: recveived 1460 bytes, wnd 11680 (5840).
>
> tcp_output: sending ACK for 3649348179
>
> tcp_recved: recveived 1460 bytes, wnd 13140 (4380).
>
> TCP header:
> +-------------------------------+
> |       80      |     4099      | (src port, dest port)
>
> +-------------------------------+
> |           3649348179          | (seq no)
>
> +-------------------------------+
> |           0000006617          | (ack no)
>
> +-------------------------------+
> |  5 |   |010000|     64240     | (hdrlen, flags (
> ACK
>
>
> ), win)
> +-------------------------------+
> |    0x7be6     |         0     | (chksum, urgp)
>
> +-------------------------------+
> +-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags
> ACK
>
>
> -+-+-+-+-+-+-+-+-+-+-+-+-+-+
Sorry, forgot attachments

dup_ack_6_lwip_1_3_2.7z
Description: Binary data

dup_ack_lwip_debug.7z
Description: Binary data