Re: [lwip-users] Communication delays, if using lwIP in different network areas

[Kieran Mansley]

On 11 Nov 2010, at 19:12, Pettinato, Jim wrote:

> Benjamin,
>  
> TCP tries to optimize network throughput by placing outgoing data on a 
> transmit queue, and sending when needed (or after a delay as you are seeing) 
> . For some connections (for example command/response type connections like 
> ModbusTCP) this is extremely inefficient because there is usually only one 
> small block of data written per outgoing packet anyway.
>  
> To circumvent the delay you are seeing, your application should call 
> tcp_output() after queuing data with tcp_write().

I can't see how that would be affected by there being a router involved though.

I think to understand this problem we'll need to see
1) a packet capture.  
2) an example of how you're configuring your netif (e.g. the call to netif_add)
3) your lwipopts.h

Thanks

Kieran