There seem to be two separate issues.
The first issue is what information from BGP would one like to correlate
with the traffic flows. I understand that there is useful information.
The motivation given in the draft seems to apply to more cases than I
thought, but still it is of limited applicability.
More importantly is the question of whether the proposed method is the
right way to get the information. As the draft acknowledges, there are
other ways to get the information. Ways that do not need new router
software much less modifications of the fast path.
There is an argument in the draft about timeliness. At least for the
use case document in the draft, that argument does not hold water.
Yours,
Joel
On 4/15/18 10:45 PM, Aijun Wang wrote:
Hi, Joel:
Can we consider this draft from other viewpoints? If the router can
report and correlate the traffic with its associated community, the
usage of the community to differentiate the customer, the service
category that be accessed and the geographical region etc. will be
flourished.
And currently, China Telecom has some internal usage regulation for
community to differentiate some important customers and the related
services.
Best Regards.
Aijun Wang
Network R&D and Operation Support Department
China Telecom Corporation Limited Beijing Research
Institute,Beijing, China.
*From:*Joel Halpern <mailto:jmh@xxxxxxxxxxxxxxx>
*Date:* 2018-04-13 22:44
*To:*rtg-dir@xxxxxxxx <mailto:rtg-dir@xxxxxxxx>
*CC:*draft-ietf-opsawg-ipfix-bgp-community.all@xxxxxxxx
<mailto:draft-ietf-opsawg-ipfix-bgp-community.all@xxxxxxxx>;
ietf@xxxxxxxx <mailto:ietf@xxxxxxxx>; opsawg@xxxxxxxx
<mailto:opsawg@xxxxxxxx>; gen-art@xxxxxxxx <mailto:gen-art@xxxxxxxx>
*Subject:* Rtgdir early review of draft-ietf-opsawg-ipfix-bgp-community-06
Reviewer: Joel Halpern
Review result: Not Ready
This is both a gen-art re-review and a routing directorate requested review.
The revisions from draft-04 to -06 show some improvement. However, I still
have serious problems with this work.
The primary problem is that this seems to violate the designed work
distribution in the IPFIX architecture. The draft itself notes that the
correlation requested could be done in the collector. Which is where
correlation is designed to be done. Instead, it puts a significant new
processing load on the router that is delivering the IPFIX information. For
example, if one delivers IPFIX from the router data plane, one either has to
modify the router architecture to include additional complex computed
information in the data plane architecture (a bad place to add
complexity) or
one has to give up and move all the information through the control
plane. And
even the control plane likely has to add complexity to its RIB logic, as
it has
to move additional information from BGP to the common structures.
The secondary problem is that this additional work is justified for the
router
by the claim that the unusual usage of applying community tags for
geographical
location of customers is a common practice. It is a legal practice. And I
presume it is done somewhere or the authors would not be asking for
it. But
it is not common.
In short, since even the draft admits that this is not needed, I recommend
against publishing this document as an RFC.
