Subject: question about the traffic engineering extensions to OSPF

From: Feihong Chen <[email-masked]>
Date: Wed, 22 Aug 2001 12:12:41 -0400

Hi, 

I just realized that the new version of the "Traffic Engineering Extensions
to OSPF (draft-katz-yeung-ospf-traffic-05.txt)" made some changes on the
Sec2.4.2 (Link TLV). Unlike the previous version of the draft, this version
proposed that "The Link Type and Link ID sub-TLVs are mandatory, i.e., must
appear exactly once. All other sub-TLVs defined here may occur at most
once." (Note, other sub-TLVs includes traffic engineering metric,
local/remote interface ip address, bandwidth information, class/color).

The question that I have here is, if the LSA only advertise the Link Type
and Link ID as mandatory, then I don't see the capability of OSPF being a
"traffic engineering helper" because the Traffic Engineering Database build
from these two information ( which is the worst case ) simply is not able to
calculate the ERO (i.e. the list of ip addresses), nor the bandwidth for an
attempted LSP. 

In another word, if the proposed extensions to OSPF is mainly for traffic
engineering, shouldn't some or all of  "other sub-TLVs" (e.g. bandwidth, ip
address, color) be necessarily advertised besides the Link Type and Link ID?
Otherwise, it will end up the traditional OSPF not for TE purpose? 

Maybe I miss something here, looking forward to a clarify to better
understand the purpose of this updated changes.

Thanks a lot,
Feihong Chen

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From: Eric Osborne <[email-masked]>
Date: Wed, 22 Aug 2001 16:00:35 -0400

Not having this info makes online path calculation of an ERO more
difficult, but an offline tool can certainly calculate paths and give
them to a LSR, which just dumbly signals what it's told.

eric