Re: [Bier] WGLC: draft-ietf-bier-php

[Greg Shepherd <[e-mail]>]

Loa,

Can you please review Jeffrey's changes to confirm they address your
concerns? If so, then we can move this along.

Thanks,
Greg

On Mon, Aug 24, 2020 at 12:06 PM Greg Shepherd <[e-mail]> wrote:

> Thanks Jeffrey and Greg. Loa, please confirm when you can that this rev
> addresses your concerns.
>
> Shep
> (chairs)
>
> On Mon, Aug 24, 2020 at 10:50 AM Jeffrey (Zhaohui) Zhang <zzhang=
> [e-mail]> wrote:
>
>> Hi Loa, Greg,
>>
>>
>>
>> I’ve submitted -06 to take care of your comments.
>>
>>
>>
>> Thanks.
>>
>> Jeffrey
>>
>>
>>
>> Juniper Business Use Only
>>
>> *From:* BIER <[e-mail]> *On Behalf Of * Jeffrey (Zhaohui)
>> Zhang
>> *Sent:* Monday, August 24, 2020 11:16 AM
>> *To:* Loa Andersson <[e-mail]>; Gyan Mishra <[e-mail]>;
>> Mankamana Mishra (mankamis) <mankamis=[e-mail]>
>> *Cc:* IJsbrand Wijnands (iwijnand) <iwijnand=[e-mail]>;
>> Greg Shepherd <[e-mail]>; [e-mail]
>> *Subject:* Re: [Bier] WGLC: draft-ietf-bier-php
>>
>>
>>
>> *[External Email. Be cautious of content]*
>>
>>
>>
>> Hi Loa,
>>
>>
>>
>> Please see zzh> below.
>>
>>
>>
>> -----Original Message-----
>> From: BIER <[e-mail]> On Behalf Of Loa Andersson
>> Sent: Saturday, August 22, 2020 1:57 AM
>> To: Gyan Mishra <[e-mail]>; Mankamana Mishra (mankamis) <
>> mankamis=[e-mail]>
>> Cc: IJsbrand Wijnands (iwijnand) <iwijnand=[e-mail]>;
>> Greg Shepherd <[e-mail]>; [e-mail]
>> Subject: Re: [Bier] WGLC: draft-ietf-bier-php
>>
>>
>>
>> [External Email. Be cautious of content]
>>
>>
>>
>>
>>
>> Working Group,
>>
>>
>>
>> I've had time to read the draft a bit more in detail..
>>
>>
>>
>> I'm convinced that this will work, and support progressing the draft.
>>
>>
>>
>> I still think there are some minor description details that could be
>> improved.
>>
>>
>>
>> The draft says:
>>
>>
>>
>>     One way to solve this problem is to use Penultimate Hop Popping (PHP)
>>
>>     so that the upstream BFR can pop the BIER header and send the payload
>>
>>     "natively" (note that the upstream BFR can be connected directly or
>>
>>     indirectly via any type of tunnel to the PE).  This is similar to
>>
>>     Multi-Protocol Label Switching (MPLS) PHP though it is the BIER
>>
>>     header that is popped.
>>
>>
>>
>> This indicate that this is a "per node" decision, while in MPLS it is a
>> per LSP decision.
>>
>>
>>
>> Zzh> It’s a per node decision for all traffic to a particular “BFER” who
>> does not really support BIER forwarding. PHP is not used when the BFERs do
>> support BIER.
>>
>>
>>
>> I would think that it is possible for one node to be the penultimate node
>> for some traffic but not for other traffic, even though the traffic is sent
>> to the same node, which can be both ultimate node, pen-ultimate node or
>> transit node.
>>
>>
>>
>>       +-------+              +-------+          +-------+
>>
>>       |       |              |       |          |       |
>>
>> -a,b-+   A   +-----a',b-----+   B   +----a'----+  CPE1 |
>>
>>       |       |              |       |          |       |
>>
>>       +-------+              +---+---+          +-------+
>>
>>                                  |
>>
>>                                  b'
>>
>>                                  |
>>
>>                              +---+---+          +-------+
>>
>>                              |       |          |       |
>>
>>                              +   C   +----b'----+  CPE2 |
>>
>>                              |       |          |       |
>>
>>                              +---+---+          +-------+
>>
>>
>>
>>
>>
>> Two streams comes in to A from the left (a and b).
>>
>>
>>
>> A is the penultimate node for traffic to to CPE1 (a) so the BIER header
>> is popped.
>>
>>
>>
>> A is not the  penultimate node for traffic to to CPE2 (b) so the BIER
>> header is not popped.
>>
>>
>>
>> Zzh> So the context is that B does support BIER. In that case, A won’t do
>> PHP for B at all.
>>
>>
>>
>> Both a' and b is sent to B.
>>
>>
>>
>> B forward a' natively to CPE1.
>>
>>
>>
>> B is the penultimate node for traffic to to CPE2 (b) so the BIER header
>> is popped.
>>
>>
>>
>> b' is forwarded to C and onto CPE2
>>
>>
>>
>> Works just fine.
>>
>>
>>
>> Question: If the PHP is a "per node decision" how is A stopped from doing
>> PHP for b?
>>
>>
>>
>> Zzh> Please see above :-)
>>
>> Zzh> Thanks.
>>
>> Zzh> Jeffrey
>>
>>
>>
>> /Loa
>>
>>
>>
>>
>>
>>
>>
>> On 22/08/2020 05:20, Gyan Mishra wrote:
>>
>> >
>>
>> > I support advancing this critical draft forward..  I agree that the PHP
>>
>> > feature traditionally used with MPLS and has been adopted by SR and
>>
>> > now by BIER for similar reasons of being able to pop the BIER header
>>
>> > similar to what is done with SR PHP concept and now extensible with
>>
>> > BIER for Non-BRF capable PE's.
>>
>> >
>>
>> > BIER IPv6 is still being developed, however I think maybe BIERin6
>>
>> > could take advantage of  PHP by popping the encapsulated L2 1/2 BIER
>>
>> > shim for "Non-BFR" capable PE.  I think for BIERv6 as the BIER header
>>
>> > is encoded in DOH it may be difficult to support PHP.
>>
>> >
>>
>> > Thanks
>>
>> >
>>
>> > Gyan
>>
>> >
>>
>> > On Wed, Aug 19, 2020 at 2:01 PM Mankamana Mishra (mankamis)
>>
>> > <mankamis=[e-mail]
>>
>> > <mailto:[e-mail] <[e-mail]>>>
>> wrote:
>>
>> >
>>
>> >     Support moving this document forward. ____
>>
>> >
>>
>> >     __ __
>>
>> >
>>
>> >     *From: *BIER <[e-mail] <mailto:[e-mail]>>
>>
>> >     on behalf of "IJsbrand Wijnands (iwijnand)"
>>
>> >     <iwijnand=[e-mail]
>>
>> >     <mailto:[e-mail] <[e-mail]>>>
>>
>> >     *Date: *Monday, August 17, 2020 at 11:56 AM
>>
>> >     *To: *Greg Shepherd <[e-mail] <mailto:[e-mail]>>
>>
>> >     *Cc: *"[e-mail] <mailto:[e-mail]>" <[e-mail]
>>
>> >     <mailto:[e-mail] <[e-mail]>>>
>>
>> >     *Subject: *Re: [Bier] WGLC: draft-ietf-bier-php____
>>
>> >
>>
>> >     __ __
>>
>> >
>>
>> >     In support moving this draft forward, ____
>>
>> >
>>
>> >     __ __
>>
>> >
>>
>> >     Thx,____
>>
>> >
>>
>> >     __ __
>>
>> >
>>
>> >     Ice.____
>>
>> >
>>
>> >     Sent from my iPhone____
>>
>> >
>>
>> >
>>
>> >
>>
>> >     ____
>>
>> >
>>
>> >         On 13 Aug 2020, at 05:31, Greg Shepherd <[e-mail]
>>
>> >         <mailto:[e-mail] <[e-mail]>>> wrote:____
>>
>> >
>>
>> >
>>
>> >         Please read and respond to this thread. We had a WGLC for this
>>
>> >         draft previously, but had no response. Let’s do better. ____
>>
>> >
>>
>> >         __ __
>>
>> >
>>
>> >
>>
>> > https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-iet
>> <https://urldefense.com/v3/__https:/datatracker.ietf.org/doc/draft-iet>
>>
>> > f-bier-php/______;!!NEt6yMaO-gk!Ws4otxDsuVKTsaEjyRKVYz-hcmmmGgDiE7Cnpq
>>
>> > vfA3s4r-JLyE8pK0PVq2FrBGNX$
>>
>> >
>>
>> >         __ __
>>
>> >
>>
>> >         Start of short LC timer. Respond by Aug 19..____
>>
>> >
>>
>> >         __ __
>>
>> >
>>
>> >         - Shep____
>>
>> >
>>
>> >         (Chairs)____
>>
>> >
>> Juniper Business Use Only
>>
>>
>>
>> >         _______________________________________________
>>
>> >         BIER mailing list
>>
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>>
>> >
>>
>> > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/bier
>> <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/bier>
>>
>> > ______;!!NEt6yMaO-gk!Ws4otxDsuVKTsaEjyRKVYz-hcmmmGgDiE7CnpqvfA3s4r-JLy
>>
>> > E8pK0PVq8rXWgdg$
>>
>> >
>>
>> >     _______________________________________________
>>
>> >     BIER mailing list
>>
>> >     [e-mail] <mailto:[e-mail] <[e-mail]>>
>>
>> >
>>
>> > https://urldefense.com/v3/__https://www.ietf.org/mailman/listinfo/bier
>> <https://urldefense.com/v3/__https:/www.ietf.org/mailman/listinfo/bier>
>>
>> > __;!!NEt6yMaO-gk!Ws4otxDsuVKTsaEjyRKVYz-hcmmmGgDiE7CnpqvfA3s4r-JLyE8pK
>>
>> > 0PVq9z6N_yR$
>>
>> >
>>
>> >
>>
>> >
>>
>> > --
>>
>> >
>>
>> > <https://urldefense.com/v3/__http://www.verizon.com/__;!!NEt6yMaO-gk!W
>>
>> > s4otxDsuVKTsaEjyRKVYz-hcmmmGgDiE7CnpqvfA3s4r-JLyE8pK0PVqyDf-6DB$ >
>>
>> >
>>
>> > *Gyan Mishra*
>>
>> >
>>
>> > /Network Solutions A//rchitect /
>>
>> >
>>
>> > /M 301 502-1347
>>
>> > 13101 Columbia Pike
>>
>> > /Silver Spring, MD
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>>
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>>
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>>
>> > __;!!NEt6yMaO-gk!Ws4otxDsuVKTsaEjyRKVYz-hcmmmGgDiE7CnpqvfA3s4r-JLyE8pK
>>
>> > 0PVq9z6N_yR$
>>
>> >
>>
>>
>>
>> --
>>
>>
>>
>> Loa Andersson                        email: [e-mail]
>>
>> Senior MPLS Expert                          [e-mail]
>> <loa.pi.nu@gmail..com>
>>
>> Bronze Dragon Consulting             phone: [phone]
>>
>>
>>
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