[Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps?

[Stephen Hemminger]

On Wed, 16 Mar 2011 00:40:28 +0200
Jonathan Morton <chromatix99 at gmail.com> wrote:

> 
> On 16 Mar, 2011, at 12:36 am, Rick Jones wrote:
> 
> > Back and forth synchronization between driver and device is
> > doubleplusungood.  Being able to remove a packet on the tx queue already
> > made known to the NIC sounds like it could become a rathole. If you are
> > lucky, you *might* have a "valid/invalid" bit in a packet descriptor
> > that the driver could hope to set before the NIC had pulled-in a copy
> > across the I/O bus.
> 
> Since this would be on the order of a second after submission, this seems unlikely then.
> 
> The even better solution would be if the hardware timed-out an old packet by itself after about 1 second.  Does this happen already?  If not, can it?
> 
>  - Jonathan

The real problem was the IEEE 802 design that does retransmit at link level and
therefore ends up being outside of control of software.