RE: Comments and questions to draft-ayyangar-inter-region-te-00.txt(long message)

Hi Arthi,

Thanks for your clarifications - a couple of additional comments below.

[snip]

Hi Christian,

Thanks a lot for your detailed comments. I have tried to address
most of your questions/comments. Please find my replies inline.

> To me, BGP clusters and confederations could also be examples of an AS
which
> would be composed of multiple regions,
--------> Yes, BGP confederation could be yet another example of a region.
But if all the members of a confed run a single IGP, then it's not
clear why each member would form a region.

CJ: I'm not sure I understand your point. All I meant is that a sub-AS (as
part of a BGP confederation) could be viewed as a region by itself.

[snip]
Also, the notion of
> "transit LSPs transported across that region" should be defined, including
a
> comparison with FA-LSP and LSP segments...since both the latter may *also*
> be viewed as transit LSP paths, at least from an intra-region TE policy.
----------> The notion of 'transit' here depends on the originating and
terminating regions. While FA-LSPs and LSP segments start and terminate in
the same region (they are intra-region), LSPs that originate in some other
region and traverse this region are viewed to be 'transit LSPs'. As far as
the inter-region TE policy goes, therefore, the inter-region LSPs would be
treated as 'transit'. Ofcourse, other TE policies, local to the region,
could also be applicable to the intra-region LSPs that transport the
inter-region LSPs.
	I am not quite clear about your last sentence "since both the
latter may *also* be viewed as transit LSP paths, at least from an
intra-region TE policy". Could you elaborate ?

CJ: what I meant is that, since FA and segments are computed to convey
traffics that relate to inter-region LSP paths, both the FA and segment LSPS
can be viewed as transit LSPs within a given domain, whereas they may have
been (pre)-computed as part of the enforcement of an intra-domain TE policy.

[snip]

> The wording "...depending on the requirement of the operator of the
transit
> region" in the last paragraph should also deserve some elaboration, since
I
> suspect the need for (contractual) agreements between (participating)
> operators (i.e. operators who would participate in the dynamic enforcement
> of an inter-region TE policy), hence the need to exchange and possibly
> negotiate related QoS requirements and (TE) capabilities.
---------> Wouldn't this depend on the nature of the region itself ?
i.e. while the above may be true for an inter-AS LSP setup, especially
when the ASes belong to different SPs, it need not be applicable to an
inter-area LSP setup. Section 8.4 addresses this for inter-AS case.

CJ: I tend to agree with you, but I'm not sure your comment is strictly
relevant since the text refers to *the operator of the transit region*,
which, to me, implictly assumes an inter-AS context: otherwise, I don't see
why an operator of a given *area* should be different from the one who
manages another area...within a given domain.

Cheers,

Christian.