Hi Ben,
On 9/26/18, 6:02 PM, "Benjamin Kaduk" <[email protected]> wrote:
Benjamin Kaduk has entered the following ballot position for
draft-ietf-ospf-segment-routing-msd-21: Discuss
When responding, please keep the subject line intact and reply to all
email addresses included in the To and CC lines. (Feel free to cut this
introductory paragraph, however.)
Please refer to https://www.ietf.org/iesg/statement/discuss-criteria.html
for more information about IESG DISCUSS and COMMENT positions.
The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-ospf-segment-routing-msd/
----------------------------------------------------------------------
DISCUSS:
----------------------------------------------------------------------
This is essentially a process discuss, and hopefully easy to resolve.
In Section 4, we say:
The meaning of the absence of both Node and Link MSD advertisements
for a given MSD type is specific to the MSD type. Generally it can
only be inferred that the advertising node does not support
advertisement of that MSD type. However, in some cases the lack of
advertisement might imply that the functionality associated with the
MSD type is not supported. The correct interpretation MUST be
specified when an MSD type is defined.
I don't think we can make this sort of normative requirement on a registry
created by a different document, at least not without updating the registry
to also point to this document.
Would you be satisfied if the same text were in both the IS-IS and OSPF
document? We really want a copy registry for IGPs (which are really only
disseminating the information) to Segment Routing capable routers in the
routing domain.
Thanks,
Acee
----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------
Can SID be expanded on first usage --
https://www.rfc-editor.org/materials/abbrev.expansion.txt does not list it
as "well known". (It also doesn't appear to list "Segment Identifier" as
one of the expansions.)
This is basically the same thing I said for the IS-IS document that creates
the MSD types registry, but I'm not sure I followed correctly the meaning
of MSD type 1 for SR-enabled vs. non-SR-enabled networks. In particular,
I still don't really understand why it's okay to use the same codepoint for
the max SID depth in SR-enabled networks and for the max label depth in
non-SR MPLS networks. Why couldn't they just be separate MSD Type
codepoints?
Section-by-section comments follow.
Section 2
If the Node MSD TLV appears in multiple Router
Information LSAs that have the same flooding scope, the Node MSD TLV
in the Router Information (RI) LSA with the numerically smallest
Instance ID MUST be used and subsequent instances of the Node MSD TLV
MUST be ignored. [...]
Unless there is a sorting requirement I've forgotten about, shouldn't this
be "other" rather than "subsequent"?
Section 6
Thanks for the updates in response to the secdir review; they help a lot.
If the value is larger than supported - instantiation of a path that
can't be supported by the head-end (the node performing the SID
imposition).
This is supposed to mean "(instantiation by the head-end) of a (path that
can't be supported)", not "instantiation of a path (that can't be supported
by the head-end)", right?
_______________________________________________
Lsr mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/lsr
