[Apn] Drafts vs. presentation

[Watson Ladd <[e-mail]>]

Dear all,

I must confess that the SAAG presentation on APN was at a time of day
when I am ordinarily asleep and my caffeine titre might not have been
as high as necessary. But what I recall in that presentation and the
framework draft seem to be at odds, and I have some rather basic
questions about this.

Firstly, it sounded like the service indications need to be parsed at
very high rate, enabling cut-through. But the drafts have variable
length TLVs with a wide variety of options, which to me would be
incompatible with this sort of processing. It seems that the same
option can carry user ids and application ids, as well as very
detailed information about desired service levels, beyond what I think
network operators could reasonably make use of. Wouldn't it be simpler
to have named classes and have a fixed 16 bit field to select this
class? or pad it out to whatever is needed for aligment beyond it. 65k
classes is enough for anybody.

Secondly the framework draft seems to want to be independent of the
underlying transport, be it MPLS, IP, etc. And I don't think that
really is necessary In my limited understanding, the sort of decision
an MPLS path element makes is extraordinarily limited: the network is
a stack machine: you pop the label, plop on a few labels, off it goes.
All the intelligence is at the entrance and exits, and there isn't
really a local view of what path is better for what policy: whole idea
of MPLS is to avoid that.

I think the proponents of this need to state the goal, and have drafts
that achieve that goal, and communicate it clearly. Otherwise I feel
like I'm grappling with a rather protean set of drafts, one that
promises all things to all people in ways that don't move the
conversation forward.

Sincerely,
Watson Ladd
-- 
Astra mortemque praestare gradatim