Subject: Re: [Pce] request timeslot for draft-wang-pce-inter-as-extentions-01

From: JP Vasseur <[email-masked]>
Date: Tue, 19 Jul 2011 15:18:08 +0200

Hi Xuerong,

On Jul 1, 2011, at 3:33 AM, <[email-masked]> <[email-masked]> wrote:

> 
> Hi,all 
> 
> I want to apply for a 10mins timeslot to represent my draft on 81th IETF meeting.The draft name is draft-wang-pce-inter-as-extentions-01. 
> By the way,I have not received the email about requesting the timeslot for 81th IETF meeting yet.Perhaps I have missing something? 
> 

Thanks for your email. Please refer to the mail sent to the list today explaining how slots have been 
allocated. In this case, you have several documents that were presented at the last IETF. We had a
good technical discussions, where people raised concerns during the meeting. So far, we have not
seen any technical discussion on the mailing list though. We'd like to encourage you to trigger some 
discussion on the mailing list.

Thanks.

JP and Julien.

> Thanks 
> Xuerong 
> 
> --------------------------------------------------------
> ZTE Information Security Notice: The information contained in this mail is solely property of the sender's organization. This mail communication is confidential. Recipients named above are obligated to maintain secrecy and are not permitted to disclose the contents of this communication to others.
> This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the originator of the message. Any views expressed in this message are those of the individual sender.
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---

From: [email-masked]
Date: Wed, 20 Jul 2011 16:02:01 +0800

Hi JP and PCEers,

Thank you for  the promotion.We would like to trigger the discussion, and 
greatly appreciate your comments and participatory.

We add some scenarios to describe why we need to extend BRPC procedure in 
the case of computing inter-as bi-directional LSP. 

Suppose the inter-AS link fails in one direction(e.g., from C1 to B1).
As border node just have unidirectional inter-AS TE link, for a 
bi-direction LSP computation from A to Z, PCE1 doesn't know 
that the link from C1 to  B1 can not be used. How PCEs select the inter-AS 
links for the bidirectional path?  

 Similarly,Suppose uni-direction LSP along A1-C-B-Z1 have already been 
setup.
After that when we setup a bi-direction LSP from A to Z, neither PCE1 nor 
PCE2 knows that whether the inter-AS link can 
satisfy the constraints in two directions or not.  

For a bi-direction path computation from A to Z :
A VSPT computed by PCE2 consists of two bi-direction optimal paths: EGZ 
and FZ. 

Suppose the uni-direction inter-AS link from D to B doesn't satisfy the 
constraints. 
Only inter-AS links C-E,D-E and D-Fcan 
satisfy the constraints in bi-direction. But neither PCE1 nor PCE2 knows 
that information,they couldn't know which inter-AS 
links should be selected.
Actually the optimal paths between exit BN of AS1 and node Z are shown in 
red color bellow,but PCE2 cannot compute 
these bi-direction optimal paths by adding the inter-AS links .  On the 
other hand, PCE1 cannot compute the 
bi-direction optimal paths by adding the inter-AS links neither (i.e.,from 
A to E and A to F)

 Thanks .

  Xuerong Wang / Best Regards

JP Vasseur <[email-masked]> 
2011-07-19 21:18

收件人
"<[email-masked]>" <[email-masked]>
抄送
Julien Meuric <[email-masked]>, Daniel King 
<[email-masked]>, [email-masked]
主题
Re: request timeslot for draft-wang-pce-inter-as-extentions-01

Hi Xuerong,

On Jul 1, 2011, at 3:33 AM, <[email-masked]> <
[email-masked]> wrote:

Hi,all 

I want to apply for a 10mins timeslot to represent my draft on 81th IETF 
meeting.The draft name is draft-wang-pce-inter-as-extentions-01. 
By the way,I have not received the email about requesting the timeslot for 
81th IETF meeting yet.Perhaps I have missing something? 

Thanks for your email. Please refer to the mail sent to the list today 
explaining how slots have been 
allocated. In this case, you have several documents that were presented at 
the last IETF. We had a
good technical discussions, where people raised concerns during the 
meeting. So far, we have not
seen any technical discussion on the mailing list though. We'd like to 
encourage you to trigger some 
discussion on the mailing list.

Thanks.

JP and Julien.

Thanks 
Xuerong 

--------------------------------------------------------
ZTE Information Security Notice: The information contained in this mail is 
solely property of the sender's organization. This mail communication is 
confidential. Recipients named above are obligated to maintain secrecy and 
are not permitted to disclose the contents of this communication to 
others.
This email and any files transmitted with it are confidential and intended 
solely for the use of the individual or entity to whom they are addressed. 
If you have received this email in error please notify the originator of 
the message. Any views expressed in this message are those of the 
individual sender.
This message has been scanned for viruses and Spam by ZTE Anti-Spam 
system.

---

From: [email-masked]
Date: Wed, 20 Jul 2011 16:27:12 +0800

Hi JP and PCEers, 

We add some scenarios to describe why we need to extend BRPC procedure in 
the case of computing inter-AS bi-directional path. 

Suppose the inter-AS link fails in one direction(e.g., from C1 to B1).
As border node just have unidirectional inter-AS TE link properties, for a 
bi-direction path computation from A to Z, PCE1 doesn't know 
that the link from C1 to  B1 can not be used. How PCEs select the inter-AS 
links for the bidirectional path?  

 Similarly,Suppose uni-direction LSP along A1-C-B-Z1 have already been 
setup.
After that we setup a bi-direction LSP from A to Z, neither PCE1 nor PCE2 
knows that whether the inter-AS link can 
satisfy the constraints in both of the directions or not.  

For a bi-direction path computation from A to Z :
PCE2 computes bi-direction optimal paths(i.e.,VSPT): EGZ and FZ. 

Suppose the uni-direction inter-AS link from E to C doesn't satisfy the 
constraints. 
Only inter-AS links C-F,D-E and D-Fcan 
satisfy the constraints in bi-direction. But neither PCE1 nor PCE2 knows 
that information, they don't know which inter-AS 
links should be selected.
Actually the optimal paths between exit BN of AS1 and node Z are shown in 
red color bellow, but PCE2 cannot compute 
these bi-direction optimal paths by adding the inter-AS links .  On the 
other hand, PCE1 cannot compute the 
bi-direction optimal paths by adding the inter-AS links either (i.e.,PCE1 
can not compute the bi-direction path from A to E and A to F).

 Thanks .

收件人

Hi Xuerong,

Hi,all 

Thanks.

JP and Julien.

Thanks 
Xuerong