Re: IGP Extensions - CCAMP Milestones

[dimitri papadimitriou <dpapadimitriou@psg.com>]

hi jean-louis

LE ROUX Jean-Louis RD-CORE-LAN wrote:

> Hi Dimitri,
>
> Thanks for the comment.
>
> As just explained by JP, the TE Node Cap TLV carries topology related
> parameters used as constraints in path computation. The leaking of
> such info across areas sounds useless as LSR TE visibility is limited
> to one area anyway... But this is, of course, open to discussions. By
> the way, do you have any application in mind where such leaking would
> be useful?

stitching capability is the major application i see for the time being - 
others will more than probably come when technology specific application 
will progress (VCAT support is a good example here but this is for 
further discussion)

note: i would like also to point out that "capability" advertisement 
that are of the following nature

1. exchanged on a per node basis
2. variation of the information value >>> LS refresh time
3. usage of the information and setting up LSP across these nodes does
   not trigger any LS update

are not scaling impacting more than any other inter-area routing 
information exchanged per current OSPF/IS-IS RFCs

> Regards,
>
> JL
>
>
>
>
>
>
>
> > -----Message d'origine----- De : JP Vasseur
> > [mailto:jvasseur@cisco.com] Envoyé : jeudi 17 novembre 2005 16:58 À
> > : Dimitri Papadimitriou; Dimitri Papadimitriou Cc :
> > zzx-adrian@olddog.co.uk; ccamp@ops.ietf.org; LE ROUX Jean-Louis
> > RD-CORE-LAN Objet : Re: IGP Extensions - CCAMP Milestones
> >
> > Hi dimitri,
> >
> > On Nov 16, 2005, at 6:30 PM, dimitri papadimitriou wrote:
> >
> >
> > > adrian,
> > >
> > > could you explain the reasoning for having a TE specific TLV in
> > > the auto-mesh document with area and AS-wide flooding scope
> >
> > while the TE
> >
> > > router cap TLV is restricted to an area flooding scope ? 
> > > shouldn't be one way or the other i.e. either restrict all TE
> > > info area-local or allow for TE router cap TLV with AS-wide
> >
> > flooding scope
> >
> > > ?
> > >
> > > note: there is nothing in the TE router cap TLV that would impact
> > >  scaling more than the TE auto-mesh TLV does
> >
> > I guess that the reason for allowing both intra and inter-area 
> > flooding scopes for automesh is obvious (we need to have TE LSP
> > mesh within areas and spanning multiple areas).
> >
> > So your question is probably why don't we allow the TE router cap
> > TLV to be flooded across the domain ? As far as I can remember JL 
> > already answered this question ... JL, could you forward your email
> > again ?
> >
> > In the meantime, I can answer it: the reason is that such TE node
> >  capabilities are used for TE LSP computation which cannot take
> > into account nodes that do not reside in the node's area.
> >
> > Thanks.
> >
> > JP.
> >
> >
> > > thanks, - dimitri.
> > >
> > > Adrian Farrel wrote:
> > >
> > >
> > >
> > > > Hi, We have two immediate milestones to address: Oct 05  First
> > > > version WG I-D for Advertising TE Node Capabilities in ISIS and
> > > > OSPF Oct 05  First version WG I-D for Automatic discovery of
> >
> > MPLS-TE mesh
> >
> > > > membership There are two personal submissions which address
> > > > these topics: draft-vasseur-ccamp-te-node-cap-01.txt 
> > > > draft-vasseur-ccamp-automesh-02.txt I propose that we move
> > > > these into the WG and then kick the tires thoroughly. Opinions
> > > > please. Thanks, Adrian .
>
>
> .