Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

From: Julien Meuric <[email-masked]>
Date: Tue, 20 Sep 2011 17:08:19 +0200

Hi PCE WG.

The framework for hierarchical PCE has been there for long, discussed 
several times and was pending the charter update. This is a poll for 
adopting draft-king-pce-hierarchy-fwk-06 as WG document. Please reply to 
this message to express either your support, i.e. you consider the I-D 
is a good foundation to address the issue, or your objection, which you 
are expected to clarify.

Thank you,

JP & Julien

---

From: "Daniel King" <[email-masked]>
Date: Tue, 20 Sep 2011 16:38:29 +0100

Hi All, 

I support H-PCE, although I am  an author of said document.  

Br, Dan.

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Julien
Meuric
Sent: 20 September 2011 16:08
To: [email-masked]
Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

The framework for hierarchical PCE has been there for long, discussed
several times and was pending the charter update. This is a poll for
adopting draft-king-pce-hierarchy-fwk-06 as WG document. Please reply to
this message to express either your support, i.e. you consider the I-D is a
good foundation to address the issue, or your objection, which you are
expected to clarify.

Thank you,

JP & Julien

_______________________________________________
Pce mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/pce

---

From: "Sadler, Jonathan B." <[email-masked]>
Date: Tue, 20 Sep 2011 15:51:55 -0500

Support

JonathanS adler

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Daniel King
Sent: Tuesday, September 20, 2011 10:38 AM
To: [email-masked]
Subject: Re: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi All, 

Br, Dan.

-----Original Message-----

Hi PCE WG.

Thank you,

JP & Julien

---

From: Ramon Casellas <[email-masked]>
Date: Tue, 20 Sep 2011 22:58:03 +0200

El 20/09/2011 17:08, Julien Meuric escribió:
> adopting draft-king-pce-hierarchy-fwk-06 as WG document. Please reply 
> to this message to express either your support, i.e. you consider the 
> I-D is a good foundation to address the issue, or your objection, 
> which you are expected to clarify.

Yes, support.

Thanks
Ramon

---

From: Dhruv Dhody <[email-masked]>
Date: Wed, 21 Sep 2011 04:12:12 +0000

Yes! I Support. 

Regards,
Dhruv

***************************************************************************************
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This e-mail and attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient's) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Julien Meuric
Sent: Tuesday, September 20, 2011 8:38 PM
To: [email-masked]
Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

Thank you,

JP & Julien

---

From: Itaru Nishioka <[email-masked]>
Date: Wed, 21 Sep 2011 14:06:05 +0900

Support

Itaru Nishioka, NEC

(2011/09/21 0:08), Julien Meuric wrote:
> Hi PCE WG.
>
> The framework for hierarchical PCE has been there for long, discussed several times
> and was pending the charter update. This is a poll for adopting
> draft-king-pce-hierarchy-fwk-06 as WG document. Please reply to this message to
> express either your support, i.e. you consider the I-D is a good foundation to
> address the issue, or your objection, which you are expected to clarify.
>
> Thank you,
>
> JP & Julien
>

---

From: Daniele Ceccarelli <[email-masked]>
Date: Wed, 21 Sep 2011 08:43:39 +0200

Yes/Support

BR
Daniele 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Julien Meuric
Sent: martedì 20 settembre 2011 17.08
To: [email-masked]
Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

The framework for hierarchical PCE has been there for long, discussed several times and was pending the charter update. This is a poll for adopting draft-king-pce-hierarchy-fwk-06 as WG document. Please reply to this message to express either your support, i.e. you consider the I-D is a good foundation to address the issue, or your objection, which you are expected to clarify.

Thank you,

JP & Julien

---

From: Oscar González de Dios <[email-masked]>
Date: Wed, 21 Sep 2011 09:47:26 +0200

Support,

Best Regards,

        Oscar

>-----Mensaje original-----
>De: [email-masked] [mailto:[email-masked]] En nombre de
>Julien Meuric
>Enviado el: martes, 20 de septiembre de 2011 17:08
>Para: [email-masked]
>Asunto: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06
>
>Hi PCE WG.
>
>The framework for hierarchical PCE has been there for long, discussed several
>times and was pending the charter update. This is a poll for adopting draft-
>king-pce-hierarchy-fwk-06 as WG document. Please reply to this message to

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---

From: Gino Carrozzo <[email-masked]>
Date: Wed, 21 Sep 2011 09:51:20 +0200

support

Gino Carrozzo

---

From: Dan Li <[email-masked]>
Date: Wed, 21 Sep 2011 16:05:53 +0800

Support!

Dan Li

---

From: Meral Shirazipour <[email-masked]>
Date: Wed, 21 Sep 2011 06:24:10 -0400

Hi,
  support.

BR,
Meral

> Sent: September-20-11 11:08
> To: [email-masked]
> The framework for hierarchical PCE has been there for long, 
> discussed several times and was pending the charter update. 
> This is a poll for adopting draft-king-pce-hierarchy-fwk-06 
> as WG document. Please reply to this message to express 
> either your support, i.e. you consider the I-D is a good 
> foundation to address the issue, or your objection, which you 
> are expected to clarify.
> 
> Thank you,
> 
> JP & Julien
>

---

From: Huaimo Chen <[email-masked]>
Date: Wed, 21 Sep 2011 12:20:40 +0000

Support!

Best Regards,
Huaimo

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Julien Meuric
Sent: Tuesday, September 20, 2011 11:08 AM
To: [email-masked]
Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

Thank you,

JP & Julien

---

From: [email-masked]
Date: Thu, 22 Sep 2011 15:05:37 +0800

Yeah/Support

B.R.

Fei

Julien Meuric <[email-masked]> 
发件人:  [email-masked]
2011-09-20 23:08

收件人
"[email-masked]" <[email-masked]>
抄送

主题
[Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

Thank you,

JP & Julien

---

From: "Margaria, Cyril (NSN - DE/Munich)" <[email-masked]>
Date: Thu, 22 Sep 2011 09:29:09 +0200

Hi, 

Yes/Support 

BR
Cyril

> From: [email-masked] [mailto:[email-masked]] On Behalf Of
> ext Julien Meuric
> Sent: Tuesday, September 20, 2011 5:08 PM
> To: [email-masked]
which
> you are expected to clarify.
> 
> Thank you,
> 
> JP & Julien
>

---

From: Olivier Dugeon <[email-masked]>
Date: Thu, 22 Sep 2011 18:22:35 +0200

Hello Julie, all,

I support the draft, but I want to take the opportunity to raise a 
common point between this draft, BRPC and inter-domain stuff in general.

IMHO, I think that it is missing something in the different proposal to 
compute inter-domain tunnel. This is related to the TED. Indeed, there 
is no proposal to collect suitable information that could help the PCE 
(in BRPC or in H-PCE) to select (compute) the AS path, and so select the 
better (regarding the request) peer PCE. Such information, like TE of 
the peering point between two ASs, are mandatory if we want to select 
alternate AS path than the one announced by BGP. If such mandatory 
information are out of scope of PCE WG, I'm afraid that, for me, their 
is no difference between the BRPC and H-PCE, instead on how PCE are 
cooperate. The result will be the same in term of path computation.

Is this make sense for the PCE WG and if yes, do you think it is 
suitable to propose a draft for that purpose (we have some ideas for 
that here) ?

Regards,

Olivier

-- 

*Olivier Dugeon*

FT/NSM/RD/CORE/M2I/CRM
Senior research engineer, QoS and network control
Phone/Fax: +33 296 05 2880/1470
Mobile: +33 6 82 90 37 85
[email-masked] <mailto:[email-masked]>

---

From: "Sprecher, Nurit (NSN - IL/Hod HaSharon)" <[email-masked]>
Date: Fri, 23 Sep 2011 09:29:23 +0200

Yes/support
Nurit

which

---

From: Ramon Casellas <[email-masked]>
Date: Fri, 23 Sep 2011 10:55:13 +0200

Dear Olivier, all

Please see inline

El 22/09/2011 18:22, Olivier Dugeon escribió:
>
> IMHO, I think that it is missing something in the different proposal 
> to compute inter-domain tunnel. This is related to the TED. Indeed, 
> there is no proposal to collect suitable information that could help 
> the PCE (in BRPC or in H-PCE) to select (compute) the AS path, and so 
> select the better (regarding the request) peer PCE. Such information, 
> like TE of the peering point between two ASs, are mandatory if we want 
> to select alternate AS path than the one announced by BGP. If such 
> mandatory information are out of scope of PCE WG, I'm afraid that, for 
> me, their is no difference between the BRPC and H-PCE, instead on how 
> PCE are cooperate. The result will be the same in term of path 
> computation.
>

As you may know, the issue of TED management and, in particular, TED 
management in the context of multi-domain path computation is raised 
regularly (including myself!) and no consensus seems to be reached.

To some extent, I understand the (architectural and functional) idea of 
keeping TED management somehow decoupled from the actual path 
computation function, as it is done in the context of single domain path 
computation, where the way the PCE obtains the TED is out of the scope 
(and in some sense, orthogonal).

However, I believe that in some cases both functions (path computation 
and TED management) are slightly coupled (border node identification, 
endpoint localization and topology aggregation for domain sequence 
selection, to name a few in which an IGP-based TED may not be 
sufficient). For what is worth, an approach that we proposed in the past 
(as well as other implementers) has been to use PCNtf with embedded 
OSPF-TE LSUs / LSAs (or XML files or any other encoding)  TED "slices".

This approach -- completely non-standard -- can be used for both 
wrapping and forwarding InterAS links [RFC5392] -- which, I agree with 
you, seems relevant for a more efficient selection of the AS path and 
would seem to address your requirement. This is briefly mentioned in 
Fatai's and Dan's draft-zhang-pcep-hpce --  the same approach can be 
used to wrap any other topological information. We did in a research 
project, including "virtual links or nodes" for topology aggregation 
(i.e. full-mesh) in H-PCE. In private communications I got the feeling 
that this is somehow "frowned upon" ;) and that AS peering and 
connectivity is managed at another (i.e. managed) level.

> suitable to propose a draft for that purpose (we have some ideas for 

I am not against such a proposal, since it is easier and simpler to 
"stick to a common way of doing things", although it is difficult to 
decide and I would understand the WG position against it, if it was the 
case. Nonetheless I, for one, would be interested in hearing your ideas :)

Thanks

Ramon

-- 
Ramon Casellas, Ph.D.
Research Associate - Optical Networking Area -- http://wikiona.cttc.es
CTTC - Centre Tecnològic de Telecomunicacions de Catalunya, PMT Ed B4
Av. Carl Friedrich Gauss, 7 - 08860 Castelldefels (Barcelona) - Spain
Tel.: +34 93 645 29 00 -- Fax. +34 93 645 29 01

---

From: Zhangfatai <[email-masked]>
Date: Sat, 24 Sep 2011 01:25:40 +0000

Yes, support.

Thanks
 
Fatai

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Julien Meuric
Sent: 2011年9月20日 23:08
To: [email-masked]
Subject: [Pce] Adoption of draft-king-pce-hierarchy-fwk-06

Hi PCE WG.

Thank you,

JP & Julien

---

From: Olivier Dugeon <[email-masked]>
Date: Mon, 26 Sep 2011 15:13:00 +0200

Hello Ramon, all,

Thanks for your comment. I'm agree with you and I just try to reactivate 
the debate too.

IMHO, if we want PCE do a good job, i.e. not only finding the shortest 
path, but also the one which fit optimally the request we need first to 
compute the AS path to know with which PCE I will collaborate. This AS 
path is not necessary the shortest one or the one provide by BGP. For 
such AS path Computation, PCE needs suitable information i.e. at least 
TE of the peering point.
Exchange such information is more a routing space and a problem of flooding.

Now the question is: can we used existing protocol (IGP-TE are good 
candidate) or do we modify PCEP for that purpose ?

Regards,

Olivier

Le 23/09/11 10:55, Ramon Casellas a écrit :
>> like TE of the peering point between two ASs, are mandatory if we 
>> want to select alternate AS path than the one announced by BGP. If 
>> such mandatory information are out of scope of PCE WG, I'm afraid 
>> that, for me, their is no difference between the BRPC and H-PCE, 
>> instead on how PCE are cooperate. The result will be the same in term 
>> of path computation.
>>
>
> To some extent, I understand the (architectural and functional) idea 
> of keeping TED management somehow decoupled from the actual path 
> computation function, as it is done in the context of single domain 
> path computation, where the way the PCE obtains the TED is out of the 
> scope (and in some sense, orthogonal).
>
> sufficient). For what is worth, an approach that we proposed in the 
> past (as well as other implementers) has been to use PCNtf with 
> embedded OSPF-TE LSUs / LSAs (or XML files or any other encoding)  TED 
> "slices".
>
> decide and I would understand the WG position against it, if it was 
> the case. Nonetheless I, for one, would be interested in hearing your 
> ideas :)
>
> Thanks
>
> Ramon
>

-- 

Orange

*Olivier Dugeon*
FT/NSM/RD/CORE/M2I/CRM
Senior research engineer, QoS and network control
Phone/Fax: +33 296 05 2880/1470
Mobile: +33 6 82 90 37 85
[email-masked] <mailto:[email-masked]>

France Telecom

---

From: Oscar González de Dios <[email-masked]>
Date: Mon, 26 Sep 2011 16:22:15 +0200

Hi Ramón, all...

        First of all, I would like to point out that we may differentiate several environments with different requirements for the multidomain problem. The PCE is scoped for any kind of network, from transport networks (OTN/SWON) with a rather limited number of domains, few interconnections, and few confidentiality issues,  transport networks with a large number of domains, MPLS networks with several administrative domains, and big IP/MPLS networks with a large number of domains with peering agreements. For each of them, a different solution for the multi-domain path computation may apply. A solution may not be scalable for one, but perfect for another. In this WG, each of us has one particular scenario in mind... so we need to clearly scope all the contributions/opinions. In my case, I have in mind more the scenario of a transport network with a reduced number of domains.

        In each of the above scenarios, different level of information can be sent to the entity in charge of computing the end to end path. Thus, I would allow different levels of information exchange, always based on a standard approach, and let each network operator choose the one that better fits the needs for the particular case. Thus, there would be a trade-off between scalability and quality of the computed paths.

        Said that, if we feel that using current standards are too complex for one scenario, or are not sufficient, then I would support going for the necessary extensions, maybe not in PCE WG, but more in the routing related WGs. If we think that, it is just a matter of specifying how to use current standards to cover the different scenarios, elaborating an informational RFC would be the best solution.

        Anyway, I would decouple the needs of the PCEP protocol (that should be focused on providing a standard way to cover the needs of the interactions between PCEs of different domains, or between a H-PCE and PCEs of different domains, a common way of representing the multidomain path with different levels of detail) and how to fill the TED (that includes which information to send, e.g. summarized information, inter-as information, etc. and the protocol to exchange it).

        So... unless we see that using IGP for feeding the routing information to the H-PCE is like to crack a nut with a sledgehammer,  I would avoid including in the PCEP protocol the routing information (even though it is easy to implement), but I agree on specifying how to exchange this information (with IGP or any other protocol) for particular scenarios. So... if we demonstrate that having a full IGP stack only brings interoperability problems, adds unnecessary complexity, consumes more resources and does not give additional value, I would support going to the simple approach of clearly specifying the LSAs to embed in PCNtf.

        We need to update soon the draft for the solution of the hierarchical PCE, so we must agree on these issues in order to have a common approach.

        Finally, I have another doubt... what about the reachability information when BGP is not used? Ramón proposed, in the scope of WSON networks, in an OFC research paper, to send the reachability information, that is the addresses reachable in a given domain, in a PCNtf as, e.g. IPv4 prefixes (in a BGP style). This information is needed by the PCE to know which is the domain of a given endpoint.

        Best Regards,

                Óscar

>Olivier Dugeon
>Enviado el: lunes, 26 de septiembre de 2011 15:13
>Para: Ramon Casellas
>CC: [email-masked]
>Asunto: Re: [Pce] PCE and TED - was: Adoption of draft-king-pce-hierarchy-
>fwk-06
>
>Hello Ramon, all,
>
>Thanks for your comment. I'm agree with you and I just try to reactivate the
>debate too.
>
>IMHO, if we want PCE do a good job, i.e. not only finding the shortest path,
>but also the one which fit optimally the request we need first to compute the
>AS path to know with which PCE I will collaborate. This AS path is not
>necessary the shortest one or the one provide by BGP. For such AS path
>Computation, PCE needs suitable information i.e. at least TE of the peering
>point.

---

From: Olivier Dugeon <[email-masked]>
Date: Mon, 26 Sep 2011 18:19:41 +0200

Hello Oscar, all,

You are totally right. We must consider all the different levels that 
PCE could address.

But, IMHO, I have more the feeling that there is an agreement to lower 
the level i.e. go down to take into account the optical, transport ... 
layers rather than go up to provide an abstract view of AS. I'm afraid 
that the upper layer stay at the IP/MPLS layer and not go beyond. So, is 
why I'm reactivating this discussion.

Perhaps, a beginning of the solution could be find in the last chapter 
17 "The Future of IS-IS" of this book "The complete IS-IS routing 
protocol (Hannes Gredler 
<http://www.books24x7.com/SearchResults.aspx?qdom=author&scol=%7Ball%7D&qstr=Hannes%20Gredler> and 
Walter Goralski 
<http://www.books24x7.com/SearchResults.aspx?qdom=author&scol=%7Ball%7D&qstr=Walter%20Goralski>)". 
You could google the book if you have not a copy of them. Authors 
suggest to use the faculty of IS-IS to manage several levels and propose 
a first table mapping to manage up to 8 different levels (section 17.3). 
This could perfectly feet the needs if operators will be agree to use it 
of course ;-)

Regards,

Olivier

Le 26/09/11 16:22, Oscar González de Dios a écrit :
>> [email-masked]<mailto:olivier.dugeon@orange-
>> ftgroup.com>
>>
>> France Telecom
>>
>>

-- 

Orange

*Olivier Dugeon*
FT/NSM/RD/CORE/M2I/CRM

France Telecom

---

From: Dhruv Dhody <[email-masked]>
Date: Tue, 27 Sep 2011 05:27:41 +0000

Hi All,

Just to continue on this discussion, I wanted to mention that there is another school of thought that has been discussed by few of the authors of HPCE. The idea is to keep the Parent-PCE's topology graph free of BNs (Boundary Nodes) and inter-AS TE link; it being composed only of neighbor domain adjacency. In this case no flooding of BNs and TE-Links via PCNtf or Routing is needed. This is esp useful when Parent PCE is used only to get domain-sequence and BRPC is applied to get the end-to-end path.

IMHO, I agree with Oscar that we should scope all the contributions/opinions based on multiple scenarios.

There are two approach to find the domain of a given endpoint, as mentioned Ramón proposal where child PCE send addresses reachable in a its domain to the Parent PCE via PCNtf. Another method is polling done by Parent PCE, it can flood the request to all child PCE to find in which domain the endpoint lies.

Regards,

Dhruv

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Oscar González de Dios
Sent: Monday, September 26, 2011 7:52 PM
To: Olivier Dugeon; Ramon Casellas
Cc: [email-masked]
Subject: Re: [Pce] PCE and TED - was: Adoption of draft-king-pce-hierarchy-fwk-06

Hi Ramón, all...

        Best Regards,

                Óscar

>[email-masked] <mailto:olivier.dugeon@orange-

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