draft-ietf-ippm-owdp-reqs-06.txt

[Randy Bush <randy@psg.com>]

From: Pekka Savola <pekkas@netcore.fi>

Seemed to be mostly sensible.

The first question that struck me was "how do you know if the OWAMP node
actually *has* the right clock?".  Do you just have to trust it, or
whatever? (NTP w/ GPS can be used to synch it technically, of course, but
that doesn't guarantee it's being done, or that there isn't a glitch in
the syncing or whatever).

I note that the first two sec considerations sections
(authentication/authorization), in particular, do not mention the
requirements for OWAMP-Test at all.

There also doesn't seem to be any reqs for authentication (or any
security) for the OWAMP-Test protocol.

Also, it looks like that the distinction between OWAMP-Test and -Control
is not sufficiently clear:

   Since measurement session setup and the actual measurement session
   (i) are different tasks; (ii) require different levels of
   functionality, flexibility, and implementation effort; (iii) may need
   to run over different transport protocols, there should exist two
   protocols: one for conducting the actual measurement session and
   another for session setup/teardown/confirmation/retrieval.  These
   protocols are further referred to as OWAMP-Test and OWAMP-Control,
   respectively.

   It should be possible to use devices that only support OWAMP-Test but
   not OWAMP-Control to conduct measurement sessions (such devices will
   necessarily need to support one form of session setup protocol or the
   other, but it doesn't have to be known to external parties).

   OWAMP-Control would thus become a common protocol for different
   administrative domains, which may or may not use it for session setup
   internally.

... but if OWAMP-Test is the only needed protocol for some environments,
would this lead to a functionality overlap (you have to be able to do some
of the OWAMP-Control functions *anyway* unless one is implying that the
OWAMP-Test includes them implicitly)?  Would there be a need to for
security of OWAMP-Test too?

Btw, I'm not sure how relevant this is operationally anymore:

   +  If practical, it should be possible to generate OWAMP-Test packets
      small enough, so that when encapsulated, each fits inside a single
      ATM cell.