config options

TcpRcvBuf=[int]KB client
      set the TCP socket receive buffer to n Kilobytes. It can be set up to the 
maximum socket size allowed by the system. This is useful in situations where 
the tcp receive window is set low but the maximum buffer size is set 
higher (as is typical). This works on a per TCP connection basis. You can also 
use this to artifically limit the transfer rate of the connection. In these 
cases the throughput will be no more than n/RTT. The minimum buffer size is 1KB. 
Default is the current system wide tcp receive buffer size.

TcpRcvBufPoll=[yes/no] client/server
      enable of disable the polling of the tcp receive buffer through the life 
of the connection. You would want to make sure that this option is enabled 
for systems making use of autotuning kernels (linux 2.4.24+, 2.6, MS Vista) 
default is no.

NoneEnabled=[yes/no] client/server
      enable or disable the use of the None cipher. Care must always be used 
when enabling this as it will allow users to send data in the clear. However, 
it is important to note that authentication information remains encrypted 
even if this option is enabled. Set to no by default.

NoneSwitch=[yes/no] client
     Switch the encryption cipher being used to the None cipher after
authentication takes place. NoneEnabled must be enabled on both the client
and server side of the connection. When the connection switches to the NONE
cipher a warning is sent to STDERR. The connection attempt will fail with an
error if a client requests a NoneSwitch from the server that does not explicitly
have NoneEnabled set to yes. Note: The NONE cipher cannot be used in
interactive (shell) sessions and it will fail silently. Set to no by default.

HPNDisabled=[yes/no] client/server
     In some situations, such as transfers on a local area network, the impact 
of the HPN code produces a net decrease in performance. In these cases it is 
helpful to disable the HPN functionality. By default HPNDisabled is set to no. 

HPNBufferSize=[int]KB client/server
     This is the default buffer size the HPN functionality uses when interacting
with nonHPN SSH installations. Conceptually this is similar to the TcpRcvBuf
option as applied to the internal SSH flow control. This value can range from 
1KB to 14MB (1-14336). Use of oversized or undersized buffers can cause performance
problems depending on the length of the network path. The default size of this buffer
is 2MB. TcpRcvBufPoll, if set to yes, will override this value. This behaviour may
change in future versions.