RE: What we disagree on RE: TE Requirements Draft-ELSP

["Sudhakar Ganti" <sganti@tropicnetworks.com>]

Shai,

If multiple BW signaling is a bad thing and yet
we want a separation (or control) of BW between
OAs of E-LSP, we can statically map the BW
ratios of OAs in the whole network (say
AF1/AF2=1/10 in your example) to solve the
equation.

The fun part is, to perform rate marking (policing)
the traffic based on single BW parameters
(peak, average and burst sizes) for multiple OAs.
Try even the simple case of static mapping !!

-Sudhakar
> -----Original Message-----
> From: owner-te-wg@ops.ietf.org [mailto:owner-te-wg@ops.ietf.org]On
> Behalf Of Shai Herzog
> Sent: Wednesday, December 05, 2001 4:05 PM
> To: 'Siva Sivabalan'; 'te-wg@ops.ietf.org'
> Subject: RE: What we disagree on RE: TE Requirements Draft-ELSP
>
>
>
>
> >-----Original Message-----
> >From: owner-te-wg@ops.ietf.org [mailto:owner-te-wg@ops.ietf.org]On
> >Behalf Of Siva Sivabalan
> >Francois,
> >
> >I totally agree with you ....
> >
> >My take is that we have to associate one and only one set of signaled
> >parameters with E-LSP, regardless of how many OAs it carries.
>
> I fully agree. Multiple BW and other parameters
> is a BADDDDD thing.
>
> >When carrying
> >multiple OAs, having different (per-OA) values for one set of
> >parameters
> >(e.g., bandwidth) and the same values for other set of
> >parameters (e.g.,
> >affinity) makes E-LSP complicated without strong incentives.
>
> Agree. But do you support multiple OAs with a single BW parameters?
>
> My point is that this doesn't make sense either because one can't
> split the
> BW between the different OAs.
>
> So, basically, if you use multiple OAs in an E-LSP, many other parameters
> (like BW, CSPF) become useless (and not permitted). This means such E-LSPs
> are only good for vanilla DiffServ (no signalled BW, no constraint routes,
> etc.). I'm not sure how usefull this could be for TE purposes.
>
> So, we're left with only the case of an E-LSP with a single OA as a
> meaningfull TE approach. (which sounds awfully close if not identical to
> L-LSP).
>
> The fact that it is on someone's wish list doesn't cure the
> problem at all.
> It is computationally impossible to solve. (i.e., my example of "How many
> watermelons and cherries can you fit together into a given size box).
>
> If you disagree, please solve the following problem given only
> the following
> information:
>
> AF1+AF2=200Mb/s; how much BW is allocated to AF1?
> (for admission control computation and queueing).
>
> Shai
>