Re: [Idr] Regarding draft-vandevelde-idr-flowspec-path-redirect//答复: IDR interim (10/26/2015) 10:00am

Gunter,

Sorry but I am afraid this does not work :(.

BGP uses notion of implicit withdraw for a given NLRI.

So for particular flow NLRI I can advertise only single PATH_ID as
subsequent NLRI with different PATH_ID will be treated as withdraw of the
former.

So if indeed as you said "..each PE the redirect tunnel will share the
unique PATH_ID .." that effectively means that for a given flow NLRI I can
advertise redirect service to only one PE pretty much killing p2mp
advantage of BGP and what's worse blocking from advertising the same flow
NLRI with any different set of actions.

Best,
R.

On Mon, Oct 26, 2015 at 6:15 PM, VAN DE VELDE, Gunter (Gunter) <
gunter.van_de_velde@alcatel-lucent.com> wrote:

> Robert,
>
> Yeah, BGP is indeed p2mp relationship… This is important to keep in mind,
> and that it is exactly why PATH-ID makes sense.
>
> With 32-bit you have 2^32 and with 128-bit you have 2^128 unique
> identifiers. That is quite a lot and will serve redirect policies in most
> networks I would assume.
>
> In manual setup it is simple for a single PE:
>
>    - Preconfigure the PE with a tunnel and map it to a given unique
>    PATH_ID
>    - This tunnel now exists, however it is not used
>    -  Now the controller (i.e. vRR) sends a flow spec rule to identify
>    the traffic using this tunnel and steers traffic into this tunnel
>
> When you have multiple PE’s using a single redirect service:
>
>    - Same setup as above, but on each PE the redirect tunnel will share
>    the unique PATH_ID reflecting the redirect tunnel service
>    - (there is no relationship that the destination is the same… just the
>    redirect service is the same)
>
> When you have 5000 of these Redirect services planned:
>
>    - Manual config will make you go crazy very soon
>    - The above can be 100% orchestrated or a mix of manual/orchestrated
>    could be used
>
>
> The benefit of redirect-to-PATH_ID facilitates that network redirect
> service it decoupled from the tunnel creation/characteristics. hence the
> setup of a mp2p tunnel is beyond the scope the path_ID redirect draft if
> that happens to be the redirect service you had in mind.
>
> G/
>
>
> From: <rraszuk@gmail.com> on behalf of Robert Raszuk <robert@raszuk.net>
> Date: Monday 26 October 2015 at 17:41
> To: Gunter Van de Velde <gunter.van_de_velde@alcatel-lucent.com>
> Cc: Lizhenbin <lizhenbin@huawei.com>, Susan Hares <shares@ndzh.com>, "
> idr@ietf.org" <idr@ietf.org>, "jgs@bgp.nu" <jgs@bgp.nu>
> Subject: Re: [Idr] Regarding
> draft-vandevelde-idr-flowspec-path-redirect//答复: IDR interim (10/26/2015)
> 10:00am - 11:30am ET update
>
> Hi Gunter,
>
> Let's observe that BGP signalling is p2mp.
>
> Now let's also notice that as you correctly state TE tunnels are rather
> custom crafted p2p entities.
>
> Then natural question comes to mind ...
>
> How good does it serve to signal identical PATH_ID to all head ends for a
> given flow while what you need to do is to map it rather uniquely in the
> network ?
>
> While in theory one could construct number of mp2p TE forwarding graphs
> each with identical PATH_ID on a per flow basis I bet in practice this was
> not the application you had in mind as its opex would be rather high as
> compared to real practical usefulness :)
>
> Side question ... How are you going to provision mp2p TE ? Are you going
> to dust-off some proposals for it from the past ? Example:
> https://tools.ietf.org/html/draft-yasukawa-mpls-mp2p-rsvpte-06
>
> Or was perhaps your plan to provision number of p2p TE tunnels from
> PCE/Controller with the identical PATH_IDs ?
>
> Cheers,
> R.
>
>
> On Mon, Oct 26, 2015 at 5:26 PM, VAN DE VELDE, Gunter (Gunter) <
> gunter.van_de_velde@alcatel-lucent.com> wrote:
>
>> Hi Robin,
>>
>> Thanks for your note.
>>
>> A tunnel is not always going over shortest path. Some tunnels are TE
>> tunnels and are deliberately not going over a shortest path. This is
>> something that draft-rosen-idr-tunnel-encaps-00 will not help to signal
>> because the tunnel-encap attribute indicates tunnel parameters used by the
>> tail-end.
>>
>> If a redirect tunnel represents a particular redirect/steering service
>> (better delay, less packet loss, non-SRLG, more BW, etc…) then it does
>> become rather complex for BGP as signalling technology because a tunnel
>> relationship is a unique between 'a headend' and ‘a tailed' device. It
>> seems better to leave tunnel-setup to dedicated tunnel-setup mechanisms
>> like PCEP, SR, etc….
>>
>> The draft redirect-to-PATH_ID is providing the means to signal a
>> flow-based redirect/steering service, and have each recipient router
>> identify using local recursion for the PATH_IDs the corresponding
>> tunnels/redirect-info. This allows for tunnel setup complexity to be taken
>> away from BGP, while at the same time BGP is doing what it is very good at
>> doing: "It signals a policy” in reliable fashion.
>>
>> Kind Regards,
>> G/
>>
>>
>>
>> From:  Idr <idr-bounces@ietf.org> on behalf of Lizhenbin <
>> lizhenbin@huawei.com>
>> Date: Monday 26 October 2015 at 16:51
>> To: Susan Hares <shares@ndzh.com>, "idr@ietf.org" <idr@ietf.org>
>> Cc: "jgs@bgp.nu" <jgs@bgp.nu>
>> Subject: [Idr] Regarding
>> draft-vandevelde-idr-flowspec-path-redirect//答复: IDR interim (10/26/2015)
>> 10:00am - 11:30am ET update
>>
>> Hi Gunter,
>>
>> Regarding your presentation, I have following comments:
>>
>> Do you mean draft-hao-idr-flowspec-redirect-tunnel is to signal tunnel
>> setup info? draft-hao-idr-flowspec-redirect-tunnel is to steer traffic to
>> the tunnel instead of signal tunnel setup.
>>
>> I am not sure if the reuse of draft-rosen-idr-tunnel-encaps-00 in the
>> draft make you confused? We just hope to  just reuses the attributes of to
>> specify the tunnel type to help steering
>>
>> the traffic to tunnel. If this is not a good way, maybe we can define new
>> attributes.
>>
>>
>>
>>
>>
>> Best Regards,
>>
>> Robin
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> *发件人:* Idr [mailto:idr-bounces@ietf.org <idr-bounces@ietf.org>] *代表 *Susan
>> Hares
>> *发送时间:* 2015年10月25日 22:07
>> *收件人:* idr@ietf.org
>> *抄送:* jgs@bgp.nu
>> *主题:* [Idr] IDR interim (10/26/2015) 10:00am - 11:30am ET update
>>
>>
>>
>> IDR WG members:
>>
>>
>>
>> Below is an updated agenda for the IDR interim on 10/26/2015.
>>
>>
>>
>> Sue
>>
>>
>>
>> ------------
>>
>> IDR interim October 26, 2015
>>
>> 10:00 - 11:30am
>>
>>
>>
>> 1. Chair's slides [10:00-10:05]
>>
>>
>>
>> 1. draft-litkowski-idr-flowspec-interfaceset-01.txt
>>
>>    speaker: Stephane Litowski
>>
>>    Time: 10:05-10:15
>>
>>
>> https://datatracker.ietf.org/doc/draft-litkowski-idr-flowspec-interfaceset/
>>
>>
>>
>> 2. draft-hao-idr-flowspec-redirect-tunnel-00
>>
>>    Speaker: Weiguo Hao
>>
>>    Time: 10:15 - 10:25
>>
>>
>> http://datatracker.ietf.org/doc/draft-hao-idr-flowspec-redirect-tunnel/
>>
>>
>>
>>
>>
>> 3. draft-vandevelde-idr-flowspec-path-redirect
>>
>>    Speaker: Gunter Van De Velde
>>
>>    Time: 10:25- 10:35
>>
>>
>> http://datatracker.ietf.org/doc/draft-vandevelde-idr-flowspec-path-redirect/
>>
>>
>>
>>
>>
>> 4. Draft Name: draft-hao-idr-flowspec-nvo3-02
>>
>>    Speaker: Weiguo Hao
>>
>>    Duration: 10:35-10:40
>>
>>    http://datatracker.ietf.org/doc/draft-hao-idr-flowspec-nvo3/
>>
>>
>>
>>
>>
>> 5. draft-liang-idr-bgp-flowspec-label-01.txt.
>>
>>    Speaker:
>>
>>    Duration: 10:40-10:45
>>
>>   http://datatracker.ietf.org/doc/draft-liang-idr-bgp-flowspec-label/
>>
>>
>>
>> 6. draft-liang-idr-bgp-flowspec-time
>>
>>    presenter: Jianjie You
>>
>>    time: 10:45-10:55
>>
>>    http://datatracker.ietf.org/doc/draft-liang-idr-bgp-flowspec-time/
>>
>>
>>
>> 7. Draft Name: draft-li-idr-mpls-path-programming-02
>>
>>    Speaker: Zhenbin Li
>>
>>    Duration: 10:55-11:05
>>
>>    http://datatracker.ietf.org/doc/draft-li-idr-mpls-path-programming/
>>
>>
>>
>> 7. Draft Name: draft-li-idr-flowspec-rpd-01
>>
>>    Speaker: Shunwan Zhuang
>>
>>    Duration: 11:05 - 11:15
>>
>>    http://datatracker.ietf.org/doc/draft-li-idr-flowspec-rpd/
>>
>>
>>
>> 8.  Discussion of Flowspec drafts
>>
>>     11:15 - 11:30am
>>
>>
>>
>>  Meeting Web-ex information
>>
>>  Monday, October 26, 2015
>>
>> 10:00 am  |  Eastern Daylight Time (New York, GMT-04:00)  |  2 hrs
>>
>>
>>
>> webex infor:
>>
>> https://ietf.webex.com/ietf/j.php?MTID=mae6cf241d3adf214033e599c3ff3143f
>>
>>
>>
>> Meeting number:            644 964 970
>>
>> Meeting password:         flow.in.nets
>>
>>
>>
>>
>>
>> Join by phone
>>
>> 1-877-668-4493 Call-in toll free number (US/Canada)
>>
>> 1-650-479-3208 Call-in toll number (US/Canada)
>>
>> Access code: 644 964 970
>>
>>
>>
>>
>>
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>

Re: [Idr] Regarding draft-vandevelde-idr-flowspec-path-redirect//答复: IDR interim (10/26/2015) 10:00am - 11:30am ET update