Re: [CCAMP] draft-ietf-ccamp-te-metric-recording-02

[John E Drake <[e-mail]>]

Yours Irrespectively,

John

> -----Original Message-----
> From: Matt Hartley (mhartley) [mailto:[e-mail]]
> Sent: Friday, August 09, 2013 1:31 PM
> To: Igor Bryskin; John E Drake; CCAMP ([e-mail])
> Cc: Matt Hartley (mhartley)
> Subject: RE: draft-ietf-ccamp-te-metric-recording-02
> 
> Igor, John,
> 
> It seems that we have a simple disagreement here about whether
> discovering the cost of a LSP over a server layer is any use at all. I don't agree
> that it's as completely useless as you assert.

JD:  I don't think it's an assertion.  There is a reason why the term 'Autonomous System'
Is used.  

> 
> While it would certainly be very hard to make much of it in the complete
> absence of other communication between the operators of the client and
> server networks, I don't think that's how things work most of the time. While
> the silicon beasts that run the network may not be able to negotiate the
> meaning of "cost", the carbon-based ones that are supposed to be in charge
> of it all are fully capable of doing so. At the very least there has to be an
> agreement to allow the LSP in the first place, and there's no reason why that
> agreement can't cover other things, such as what costs are going to mean or
> how they should be interpreted.

JD:  You seem to be implicitly agreeing that providing this information Is useless
unless there is an out of band mechanism that provides a context for it.   Given this,
it hardly seems worth the trouble to embed TE metric accumulation in the RSVP-TE
signaling, since the out of band mechanism can provide TE metrics itself.
  
> 
> Granted, there will be times when this absolutely isn't the case, but I don't
> think the operators of client and server networks are always completely at
> arm's length. I think this is what Zafar meant when he said it was a policy
> matter.

JD:  This is somewhere between speculation and assertion.

> 
> It seems to me that the uselessness (or usefulness) of discovering the cost of
> a LSP over a server network is a decision best made by the network
> operators, rather than a decision that should be forced onto the network
> operator by us. I'm therefore in favour of leaving it in place so that it may be
> used by those who wish to.

JD:  So, we are supposed to create all sorts of random protocol extensions in the
hope that someone somewhere someday will find a use for them?

I have seen far too many pointless additions to RSVP-TE signaling and we have to
start using some common sense.

> 
> Cheers
> 
> Matt
>