Use of TCP_NODELAY in commercial SSH

Tobias Ringstrom tori at
Fri Feb 1 08:29:51 EST 2002

In order to test my overlapping request path for sftp on another ssh 
server, I downloaded ssh2 version 3.1.0 from  Having downloaded 
it, I decided to study the use of TCP_NODELAY in that implementation.  
Here's what I found:

* Both ssh2 and sshd2 has a NoDelay config option which is false by 

* The ssh2 client does not enable or disable NoDelay because of a channel
  type (such as pty or X11).

* The sftp2 client uses "-o NoDelay=yes" when starting its ssh "proxy" 
  which helps get, but not put.

* The sftp2 server does not enable NoDelay (since there is no way to do so 
  I guess).


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