Re: [EXT] Re: [ippm] New QUIC Packet Loss Measurement (draft-cfb-ippm-spinbit-measurements)

["Bulgarella Fabio (Guest)" <[e-mail]>]

Hello Dmitri,

> I do not understand this part.  Problems in which protocol
> implementation do you mean -- the loss measurement protocol
> or some other protocol?  If the former, I do not understand
> what you mean by "our portion of code:"  Each implementer will
> write his own code, with his own bugs.

Sorry, I didn't explain this very well. What I meant was that the implementation of our solution is "untied" from the network protocol one.
In QR logic there are no dependencies on internal protocol events (packet declared lost) that can differ in different implementations.
Changes in the network protocol implementation will not require any changes in our logic. The same cannot be said for your solution.

> I already covered this, but I believe it can bear restating:
> Besides loss measurement, a probe should aid to locate the source
> of the loss: upstream or downstream.  A single QR probe cannot do it.
> Do you not agree that locating loss source is one of the probe's goals?

It is more interesting to know if a problem occurs in our domain or outside. And this is done by the Qbit (With 2 probes).
However, it is not uncommon to be able to intercept the whole traffic of a connection by observing a single point.
In this case, all the necessary measurements can be made.

Fabio B.


________________________________________
Da: Dmitri Tikhonov <[e-mail]>
Inviato: mercoledì 22 aprile 2020 22:05
A: Bulgarella Fabio (Guest)
Cc: Lubashev, Igor; Ian Swett; Cociglio Mauro; [e-mail]; Riccardo Sisto; [e-mail]; [e-mail]; IETF IPPM WG ([e-mail])
Oggetto: [EXT] Re: [ippm] New QUIC Packet Loss Measurement (draft-cfb-ippm-spinbit-measurements)

Hello,

On Wed, Apr 22, 2020 at 07:11:38PM +0000, Bulgarella Fabio (Guest) wrote:
> 4. First of all, our solution is not dependent on any specific protocol
> implementation unlike the QL and therefore there shouldn’t be problems
> related to the quality of the implementation. In other words, our
> portion of code is always the same, in every protocol implementation.

I do not understand this part.  Problems in which protocol
implementation do you mean -- the loss measurement protocol
or some other protocol?  If the former, I do not understand
what you mean by "our portion of code:"  Each implementer will
write his own code, with his own bugs.

> Secondly, as anticipated in point 2, by observing only one direction
> we can measure the losses in the operator's domain (Qbit) and the
> end-to-end in the opposite direction (Rbit). So, our solution does work
> also for asymmetric path segments.

I already covered this, but I believe it can bear restating:
Besides loss measurement, a probe should aid to locate the source
of the loss: upstream or downstream.  A single QR probe cannot do it.
Do you not agree that locating loss source is one of the probe's goals?

  - Dmitri.