Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
X-Authentication-Warning: slinky.cs.nyu.edu: pechtcha owned process doing -bs
Date: Thu, 1 May 2003 11:23:29 -0400 (EDT)
From: Igor Pechtchanski <pechtcha AT cs DOT nyu DOT edu>
Reply-To: cygwin AT cygwin DOT com
To: brian AT genisio DOT org
cc: cygwin AT cygwin DOT com
Subject: Re: SSH tunneling buffers...
In-Reply-To: <20030501150539.74650.qmail@web20810.mail.yahoo.com>
Message-ID: <Pine.GSO.4.44.0305011122070.25128-100000@slinky.cs.nyu.edu>
Importance: Normal
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Thu, 1 May 2003, Brian Genisio wrote:

> Hi all...
>
> I am using SSH to tunnel (Using LocalForwarding ports) from one application to
> another.  The system exists of a controller software in Linux (where the SSH
> server resides), and the actual software in Cygwin.
>
> Cygwin connects to the Linux SSH server and sets up a port forward.  The Linux
> app sends a small amount of data (about 12 bytes) 30 times per second.
>
> The problem is that the Cygwin/SSH side of the tunnel is buffering the data
> before it sends it to the Cygwin app.  The result is the data is received in
> bursts, and the control is not fluid.
>
> I have tried this system in a Linux to Linux situation, and the buffering did
> not happen.  Also, I have tried sending data from Cygwin to Linux, and the
> buffering does not happen.  It only happens when data is being sent from Linux
> to Cygwin.
>
> I have also tried switching between LocalForward and RemoteForward, and it is
> the dirction that matters, not the type of port forwarding.
>
> Both sides sets the TCP_NODELAY flag before it starts sending, and I know the
> SSH code does the same...
>
> Any ideas?
> Brian

Brian,

Does "ssh -vvv" show anything that could be related to this?
	Igor
-- 
				http://cs.nyu.edu/~pechtcha/
      |\      _,,,---,,_		pechtcha AT cs DOT nyu DOT edu
ZZZzz /,`.-'`'    -.  ;-;;,_		igor AT watson DOT ibm DOT com
     |,4-  ) )-,_. ,\ (  `'-'		Igor Pechtchanski
    '---''(_/--'  `-'\_) fL	a.k.a JaguaR-R-R-r-r-r-.-.-.  Meow!

Knowledge is an unending adventure at the edge of uncertainty.
  -- Leto II


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/