Re: [lwip-users] How to force dup ACK

[Kieran Mansley]

On Thu, 2010-04-15 at 15:32 +0800, yueyue papa wrote:
> Hi All,
> 
> I use lwIP in GPRS environment.  Wireshark is setup in the server.  I
> find these information:
> 
> lwip  device  <--------------------> server (Wireshark running there)
> 
> if  TSS = 512, the TCP stream is working very stable.
> 
> if TSS = 1024, 1460, there is always TCP ACK lost in server. The
> resend is always happen.
> 
> The resend cause the performance down.

Are you sure it is ACKs that are being lost rather than packets with
payload?  Could you post an example wireshark capture to show this?

> Is there a solution I could configure lwIP make duplicate ACK send, so
> as to decrease the ACK lost possibility?

Not that I know of.  

Kieran