Hi Robert,

I am not a co-author of the draft but am interested in the problem. In fact, 
the problem was discussed year ago in nvo3 mailing list.

BGP RTs are used for controlling route distribution and BGP route distribution 
specified in rfc4364 is the pure "push" mechanism. This draft intention is to 
implement a "pull" capability in BGP/VPN. The solution you proposed can solve 
the v-spoke/v-hub use case described in the draft but, IMHO, it still uses 
"push" mode, i.e. under v-hub solo control. So it may not apply to other "pull" 
scenarios.

I am not sure yet that implementing "pull" capability by BGP RT and rfc4684 is 
the right way and like to hear your opinion on it. IMO: ORF has the native 
"pull" characteristic.

Regards,
Lucy

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of 
Robert Raszuk
Sent: Friday, October 11, 2013 4:18 PM
To: Ronald Bonica
Cc: [email protected]
Subject: Re: FW: New Version Notification for 
draft-bonica-l3vpn-orf-covering-prefixes-00.txt

Hi Ron,

I have reviewed the proposed draft. I think it is very well written document. 
Maybe this is just my own observation, but during digesting it I have struggled 
to understand why authors have decided to extend ORF rather then update 
RFC4684. Maybe if the draft will progress a bit of clarification would be nice 
as in general 4684 is preferred over ORF in VPN context.

But this is sort of minor detail. Much more important is to observe that major 
advantage of RFC7024 is that by default it works with currently deployed PEs 
and RRs. This draft however requires upgrade of both spoke PEs as well as RRs 
serving such spoke PEs. Such upgrade may or may not be always feasible.

It appears however that there is possibility of addressing the problem with 
alternative approach fully controlled by the V-hub. Such V-hub alone is capable 
of observing the flow patterns among it's V-spokes and based on the set 
threshold locally injecting into any VPN optimal route for heavy flows with 
RT-RED-FROM-HUB extended community. That as such will allow for optimal data 
flows within given VPN bypassing the V-hub.

The question arises how would we remove such more specific routes from V-spokes 
when the flow terminates ... while there is number of possible solutions in 
this space - simplest seems to be time driven.
V-hub could start timer of x minutes (configurable) after injecting more 
specific and upon expiration withdraw such more specific routes.
At most if the flow still continues customer VPN would experience transient 
sub-optimality - no drops and no significant impact as V-hub would re-advertise 
the active more specifics again.

The major advantage of such proposal is that it is readily deployable into any 
of the today's L3VPN network by only activating V-hub which could be a single 
upgraded PE or new box in the network. Moreover this procedure does not require 
any protocol extension nor additional features like new RT insertion on the 
VPNv4/v6 route reflectors which your draft requires.

I hope authors of draft-bonica-l3vpn-orf-covering-prefixes will evaluate such 
alternative.

Best regards,
R.


On Mon, Sep 16, 2013 at 4:33 PM, Ronald Bonica <[email protected]> wrote:
>
> Please review this draft and provide comments.
>
>                                Ron
>
>
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]]
>> Sent: Monday, September 16, 2013 10:15 AM
>> To: Ronald Bonica; Yakov Rekhter; Huajin Jeng
>> Subject: New Version Notification for 
>> draft-bonica-l3vpn-orf-covering- prefixes-00.txt
>>
>>
>> A new version of I-D, draft-bonica-l3vpn-orf-covering-prefixes-00.txt
>> has been successfully submitted by Huajin Jeng and posted to the IETF 
>> repository.
>>
>> Filename:      draft-bonica-l3vpn-orf-covering-prefixes
>> Revision:      00
>> Title:                 Covering Prefixes Outbound Route Filter for BGP-4
>> Creation date:         2013-09-15
>> Group:                 Individual Submission
>> Number of pages: 10
>> URL:             http://www.ietf.org/internet-drafts/draft-bonica-
>> l3vpn-orf-covering-prefixes-00.txt
>> Status:          http://datatracker.ietf.org/doc/draft-bonica-l3vpn-
>> orf-covering-prefixes
>> Htmlized:        http://tools.ietf.org/html/draft-bonica-l3vpn-orf-
>> covering-prefixes-00
>>
>>
>> Abstract:
>>    This document defines a new ORF-type, called the "Covering Prefixes
>>    ORF (CP-ORF)".  The CP-ORF is applicable in the context of a Virtual
>>    Hub-and-Spoke VPN.  It may also be applicable in other BGP/MPLS VPN
>>    environments.
>>
>>
>>
>>
>>
>> Please note that it may take a couple of minutes from the time of 
>> submission until the htmlized version and diff are available at 
>> tools.ietf.org.
>>
>> The IETF Secretariat
>>
>>
>

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