Re: OSPF ASON Routing Solution

["Igor Bryskin" <[e-mail]>]

Dimitri,

Please, see in line.

Igor

----- Original Message ----- 
From: <[e-mail]>
To: "Igor Bryskin" <[e-mail]>
Cc: "Acee Lindem" <[e-mail]>; "Adrian Farrel" <[e-mail]>;
<[e-mail]>; <[e-mail]>
Sent: Thursday, July 20, 2006 8:05 PM
Subject: Re: OSPF ASON Routing Solution


> the comment of acee will be addressed - stated already in previous e-mail
> b/f IETF 66 meeting -
>
> as ASON RC(PC) are OSPF engines defined in RFC 2328, routing info exchange
> makes use of RFC 2370 mechanism (which afaik is an intrinsic part of
> OSPF), etc., information encoding (in top-level TLVs) are defined in RFC
> 3630 and co. whereas all these are under OSPF WG resp. ... this leads me
> to the question if not extensions to OSPF - extensions of which protocol ?

RFC2370 does not provide a way for extending OSPF, rather, it exposes OSPF
advertising, flooding and synchronization mechanisms to be used by other
(non-OSPF) applications. OSPF-TE, ASON OSPF, L1VPN OSPF. mesh membership,
node capability discovery, etc. are such applications. To answer your
question OSPF-TE is not an extension to OSPF, rather, it is a separate
protocol.

Let me prove you this point. Consider RSVP (RFC2205) and RSVP-TE. The latter
*is* an extension of the former, because it understands and uses all basic
elements, objects (e.g. SESSION, SENDER_TEMPLATE, etc.) and *in addition* it
introduces new elements/objects (e.g. SESSION_ATTRIBUTES, LABEL, etc.). You
can say that RSVP-TE is a superset of RSVP. likewise, GMPLS RSVP is a
superset of RSVP-TE.
Let us now consider OSPF and OSPF-TE. The latter neither understands nor
uses basic OSPF LSAs type 1,2,3,4,5. Rather it understands only opaque LSAs
(type 10) with semantics specifically designed for the TE application. These
semantics are not understood by OSPF. You surely can not claim that OSPF-TE
is a superset of OSPF, hence OSPF-TE is not an extension to OSPF.
Furthermore, TE routing areas do not have to match IP routing areas and may
have completely different area hierarchies. ASON OSPF (I forgot the name of
the author) is a shining proof to that.

>
> the main point is that RFC 2370 stating "The information contained in
> Opaque LSAs may be used directly by OSPF or indirectly by some application
> wishing to distribute information throughout the OSPF domain." puts your
> comment in the old battle field bucket since Opaque LSAs have been applied
> since many years to (OSPF-)TE, and GR applications ... hence, are you also
> objecting to these and suggest to have a specific and dedicated protocol
> mechanism per application

I can see how OSPF can use opaque LSAs for experimantation purposes and for
extending itself, but this is not what,say, OSPF-TE is about.

>
> ps: i forgot the name of the author of OSPF ext. for L1VPN

If you are talking about L1VPN-OSPF, this is not OSPF ext for L1VPN, rather,
OSPF based L1VPN auto-discovery solution

Igor

>
>
>
>
> "Igor Bryskin" <[e-mail]>
> Sent by: [e-mail]
> 21/07/2006 00:05
>
>         To:     "Acee Lindem" <[e-mail]>, "Adrian Farrel"
> <[e-mail]>
>         cc:     <[e-mail]>
>         Subject:        Re: OSPF ASON Routing Solution
>
>
> Hi Acee,
>
> I agree with your comment 100%. OSPF IGP developed and maintained in the
> OSPF WG  and
> ASON OSPF have just one thing in common - they share the same transport ,
> but, otherwise, have 0 in common. In particular, I believe ASON OSPF
> should
> not be considered as an extension to OSPF
> and should not be objected or supported by OSPF WG.
>
> Igor
>
> ----- Original Message ----- 
> From: "Acee Lindem" <[e-mail]>
> To: "Adrian Farrel" <[e-mail]>
> Cc: <[e-mail]>
> Sent: Thursday, July 20, 2006 5:40 PM
> Subject: Re: OSPF ASON Routing Solution
>
>
> > Hi Adrian, Dimitri, et al,
> >
> > No objection on my part. However, I wanted to make a clarification that
> > may or may not be obvious to everyone. In Montreal, Dimitri
> > and I sat down and discussed my comments on the hierarchical
> > dissemination of ASON routing information between RAs (Routing Areas
> > in ASON parlance).
> >
> > Today OSPF does not support an area hierarchy other than the
> > backbone and non-backbone areas. This specification for ASON  should
> > not be considered a partial specification of support in OSPF for a new
> > area hierarchy (specific requirements are stated in the CCAMP
> > document references). Rather, it should be conceptually viewed as rules
> > for importing and exporting GMPLS TE data between separate
> > OSPF instances  (one instance per ASON RA). This was the motivation
> > for my comment on restating the inter-RA advertisement rules in term of
> > import/export rather than flooding.
> >
> > Thanks,
> > Acee
> >
> > Adrian Farrel wrote:
> > > Just a refresh in case you were travelling.
> > >
> > > I am seeking objections to this draft becoming a WG document.
> > >
> > > Adrian
> > > ----- Original Message ----- From: "Adrian Farrel"
> <[e-mail]>
> > > To: <[e-mail]>
> > > Sent: Wednesday, July 12, 2006 8:10 PM
> > > Subject: OSPF ASON Routing Solution
> > >
> > >
> > >> Hi,
> > >> On Monday in CCAMP we discussed
> > >> draft-dimitri-ccamp-gmpls-ason-routing-ospf-00.txt the solutions
> > >> draft for OSPF in ASON routing.
> > >>
> > >> There is agreement from the OSPF WG chair that we are not treading on
> > >> toes, and the meeting seemed to say that this was pretty stable.
> > >>
> > >> So a this is a quick poll to see if anyone objects to this becoming a
> > >> WG draft.
> > >> NB, this is a charter item and we have an obligation to work on this
> > >> for the ITU-T.
> > >>
> > >> Thanks,
> > >> Adrian
> > >>
> > >> PS Note that a solution does not have to be 100% perfect to become a
> > >> WG draft.
> > >>
> > >>
> > >>
> > >>
> > >>
> > >
> > >
> >
>
>
>
>