RE: [lwip-users] Optimizing TCP writes

[Bill Auerbach]

> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On Behalf
> Of Jonathan Larmour
> Sent: Wednesday, March 05, 2008 9:11 AM
> To: Mailing list for lwIP users
> Subject: Re: [lwip-users] Optimizing TCP writes
> 
> Bill Auerbach wrote:
> >
> > Is there a way to call tcp_write and defer the output?  I know I have
> > several small chunks of data going out and each is sent separately with
> > tcp_write.  If I can get lwIP to build the outgoing segment list and
> > send them all at once performance would improve a lot.
> 
> That's intrinsic to tcp_write. tcp_write only enqueues. It needs
> tcp_output
> to actually send anything (possibly called via tcp_output_nagle as you
> notice below...)

Without using tcp_output_nagle, I still see the same behavior.  Each segment
is in its own Ethernet frame.  I proved this by stopping at the low level
output routine and seeing each packet is small with the small piece of data
I used with tcp_write.

Is this normal or have I still done something wrong?

Bill