Re: Reverse port forward channel performance

[Gearoid Murphy <gearoid.murphy@xxxxxx>]

Hi Aris,

I'm not sure if it's significant but the logs from the port forwarding 
implementation show that the function 'channel_rcv_change_window' makes 
changes to the window size but in the reverse port fowarding 
implementation, changes to the window size are executed via the 
'grow_window'
function.

 - Gearoid

On 27/01/12 20:42, Aris Adamantiadis wrote:
> Hi Gearoid,
>
> It's possible that channel windows are not initialized the same way in 
> forward and reverse forwarding. This could result in bad performances 
> if the window is too small.
>
> I'll check if I can find anything.
>
> Aris
>
> Le 27/01/12 18:16, Gearoid Murphy a écrit :
> > Hi,
> >
> > We've been observing poor throughput (230KB/s) on libssh channels
> > generated from reverse port forwarding (ssh_forward_accept) via an
> > OpenSSH server.
> >
> > Conversely, when using a channel generated through a normal port
> > forwarding call (ssh_channel_open_forward), we observe far greater
> > throughput (8MB/s).
> >
> > Has anyone observed or experienced similar issues?, is there some
> > configuration aspect of the channel setup which needs to be modified?
> >
> > libssh 0.5.2-1
> > Linux 3.0.0-15-generic x86_64 x86_64 x86_64 GNU/Linux
> > openssh-server 1:5.8p1
> >
> > Thanks
> > - Gearoid