[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: accepting draft-fedyk-bgp-te-attribute-02.txt as a CCAMP WG document



Hi JP,

You define a new BGP
attribute to carry some Link attributes whereas we propose to define a
generic BGP attribute used to carry TE Link attributes that have already
been defined for IGPs.

Can you also clarify what NLRI/NLRIs this new attribute will be "attached" to ? In IGPs we do flood links and nodes ... in BGP we distribute reachability to particular prefixes.

Also could you clarify how based on such NLRI it will be inserted into TE database in the peering AS ?

Thx,
R.


Hi Yakov,

[snip]

 >>>
 >>> With all this in mind let me suggest that if you think BGP needs
 >>> to carry more information than what is currently defined in
 >>> draft-fedyk-bgp-te-attribute, then after CCAMP WG accepts
 >>> draft-fedyk-bgp-te-attribute as a CCAMP WG document you get consensus
 >>> of the CCAMP WG that this information is indeed has to be added,
 >>> and then we'll add it to the document.
 >>
 >> Well this is the approach of (potentially) redefining everything as
 >> opposed to carrying the IGP TE TLV in that new BGP attribute ?
 >
 > Here is the list of IGP(OSPF) TE TLVs, as defines in rfc3630:
 >
 >       1 - Link type
 >       2 - Link ID
 >       3 - Local interface IP address
 >       4 - Remote interface IP address
 >       5 - Traffic engineering metric
 >       6 - Maximum bandwidth
 >       7 - Maximum reservable bandwidth
 >       8 - Unreserved bandwidth
 >       9 - Administrative group
 >
 > rfc4203 adds the following TE TLVs to the above list:
 >
 >      11 - Link Local/Remote Identifiers
 >      14 - Link Protection Type
 >      15 - Interface Switching Capability Descriptor
 >      16 - Shared Risk Link Group
 >
 > Do you propose to carry all of the above TLVs in a single BGP
 > attribute ?
 >
 > If yes, do you propose to carry just what is listed above, or do
 > you propose to carry some other TLVs, in addition to what is listed
 > above ?
 >
 > If you propose to carry only some (but not all) of the above TLVs,
 > then which of the above TLVs do you propose to carry ?

I think that we first need to agree on the approach ... You define a new BGP
attribute to carry some Link attributes whereas we propose to define a
generic BGP attribute used to carry TE Link attributes that have already
been defined for IGPs. If, as I think, your intention is to carry in that
BGP attributes physical link attributes (as opposed to any form of
aggregated TE information), then why not reusing existing TE TLVs that have
already been defined for IGPs ?

If we agree to adopt this approach, my proposal was to (1) define a generic
BGP attribute with (2) application use cases companion documentS.

(1) Could be yours if you agree with the changes.
(2) draft-vasseur-ccamp-ce-ce-te could point to (1) and document the CE to
CE use case.

Thoughts ?

Thanks.

JP.

 >
 > Yakov.