Re: [tcpm] New Version Notification for draft-touch-tcpm-tcp-edo-01.txt

[Bob Briscoe <[e-mail]>]

John,

We needed to lose 7B and we've lost 8B.
So (SACK + MPTCP + TCP-AO + widespread basic options, incl 
TCPtimestamp) do fit in a SYN, therefore the example in the draft is valid.

However, as everyone has pointed out, jubilation may be short-lived. 
For instance, even now, people are working on a lower latency MPTCP 
that will need more option space.

Thx.


Bob


At 15:14 30/05/2014, Christoph Paasch wrote:
>On 30/05/14 - 13:50:44, John Leslie wrote:
> > Bob Briscoe <[e-mail]> wrote:
> > >
> > > I was asking for an example of something useful that /can/ be 
> done with EDO.
> > >
> > > I'm sure you can come up with one. However, you have shown
> > > conclusively that the example in the draft (SACK + MPTCP + TCP-AO),
> > > when added to the widespread basic options, /cannot/ be done with
> > > EDO, because it needs 7 more bytes of options than a SYN allows.
> >
> >    The claim that MPTCP needs 20 bytes in the SYN is getting on my
> > nerves...
> >
> >    As I read RFC 6824, it seems pretty clear that the initial SYN calls
> > for 12 bytes, not 20. It's the SYN-ACK that uses 20. Somebody please
> > correct me if I'm reading this wrong.
>
>Indeed, it uses 12 bytes on both the SYN and the SYN/ACK.
>
>Only the third ACK carries 20 bytes.
>
>
>Cheers,
>Christoph

________________________________________________________________
Bob Briscoe,                                                  BT