Server/Client Alive mechanism issues

[Jeff Mitchell]

On 01/25/2012 05:06 PM, Gert Doering wrote:
> Hi,
> 
> On Wed, Jan 25, 2012 at 12:26:34PM -0500, Jeff Mitchell wrote:
>> My understanding is that since the alive mechanism is running inside the
>> encrypted connection, OpenSSH would be able to (and would) prioritize
>> the alive packets over other data. So if any data is able to get through
>> (and it does) the alive packets should be able to as well. But this
>> doesn't seem to be the case.
> 
> For that, OpenSSH would need to know that there is congestion, and 
> throttle it's send rate to avoid buffers building up *elsewhere*.

It isn't really the buffers elsewhere that are the problem...I don't
really care if those buffers build up, but I *do* care if OpenSSH
terminates the connection so they can never drain.

I guess I figured that OpenSSH would already have some insight into the
state of its connection (or be performing something like
double-buffering) simply for its own performance optimization, and thus
would have an idea as to whether its channel was saturated, at which
point it could ensure to carve out some space for its own purposes.

--Jeff