RE: Comments on draft-jounay-pwe3-leaf-initiated-p2mp-pw-01

[<frederic.jounay at orange-ftgroup.com>]



Hi Xinquan,

 

"In my opinion, your original intention is to propose leaf-initiated mode as a solution for inter-domain scenario, and source-initiated mode for intra-domain scenario. Am I right?"

 

not really, actually both procedures (leaf or source initiated)  are not limited in their operating principles and as such could be used  to cover SS-PW and MS-PW configuration.  

For the standardization work we propose to focus first on P2MP SS-PW  as it is the simplest configuration, to agree on the required new  building blocks : FEC element, signaling procedures etc...   

The part related to P2MP SS-PW setup in the leaf-initiated draft and the part related to P2MP MS-PW setup in the source-initiated draft should be added asap or considered in a separate document.

 

Regarding their network applicability the choice between both approaches will have to be made on a case by case basis, driven by architectural and operational constraints. For the moment we felt the need to investigate both solutions in parallel.

 

Do you have any comment on the applicability of the two approaches ?  Or any specific requirement that would need to be included in the requirements draft on P2MP PW ?

 

Best Regards,

 

Fred

---

De : l2vpn-bounces at ietf.org [mailto:l2vpn-bounces at ietf.org] De la part de zhang.xinquan at zte.com.cn
Envoyé : mardi 21 avril 2009 03:23
À : JOUNAY Frederic RD-RESA-LAN
Cc : l2vpn at ietf.org; l2vpn-bounces at ietf.org; pwe3 at ietf.org
Objet : 答复: RE: Comments on draft-jounay-pwe3-leaf-initiated-p2mp-pw-01

Hi Frederic, 

Thanks for your clarificaton. 

You have two drafts about P2MP PW signaling, one is leaf-initiated mode 
and the other is source-initiated mode. In my opinion, your original intention 
is to propose leaf-initiated mode as a solution for inter-domain scenario, and 
source-initiated mode for intra-domain scenario. Am I right? Or your have other 
considerations? 

Best regards! 

Xinquan Zhang 

2009/4/21

<frederic.jounay at orange-ftgroup.com>
发件人:  l2vpn-bounces at ietf.org

2009-04-20 20:55

收件人	<zhang.xinquan at zte.com.cn>
抄送	l2vpn at ietf.org, l2vpn-bounces at ietf.org, pwe3 at ietf.org
主题	RE: Comments on draft-jounay-pwe3-leaf-initiated-p2mp-pw-01

Hi Xinquan, 
  
Please see my answer inline [FJ] 
  
Best Regards, 
Fred

---

De : zhang.xinquan at zte.com.cn 
[mailto:zhang.xinquan at zte.com.cn] 
Envoyé : mercredi 15 avril 2009 
07:50
À : JOUNAY Frederic RD-RESA-LAN
Cc : l2vpn at ietf.org; 
l2vpn-bounces at ietf.org
Objet : Comments on 
draft-jounay-pwe3-leaf-initiated-p2mp-pw-01


Hi, Frederic, 

I have read 
draft-jounay-pwe3-leaf-initiated-p2mp-pw-01 and have some comments. please see 
below: 

1、section 
5.4. Configuration 
   
  After configuring on each T-PE 
the attached AIIs, it is assumed that 
  all the PEs (Ingress/Egress 
T-PEs and all S-PEs) maintain an AII PW 
  routing table which gives for 
each AII as entry the "next hop" to 
  reach that AII. This AII routing 
table can be filled manually or 
  updated dynamically by means of some 
extended routing protocol like 
  proposed in [DYN MS-PW]. The 
construction of the table is out of 
  scope of the present document. 
   
  Each PE relies on its AII PW routing table to select 
the next hop PE 
  (S-PE or T-PE) to reach a given AII. 

>1  Does this AII 
routing table include both TAII and SAII? 
[FJ] Yes, the AII routing 
table dynamically populated (BGP, OSPF, IS-IS or LDP) should maintain both. The 
Egress T-PE joins the PW tree by initiating a Label Map whose the FEC contains 
the SAII, the PW tree source. Hence upon receipt of the message the S-PE does a 
lookup to select the NH to reach this SAII.      
>2  In S-PE, this AII routing table includes all the AII, or 
just part of the AII( e.g. which are in its dowstream)? 
[FJ] the AII routing table should 
be used also for VPWS or VPLS, so bidirectional PW. Therefore the AII routing 
table must reflect all the AII configured on T-PEs. Of course agregate AII 
format (i.e. w/o ACID info) as defined in [DYN MS-PW] must be used to optimize 
the AII routing table

2、Section 5.7. Using TAII Leaf Sub-TLV 
   
  
Section TBD 
   
  The TAII Leaf sub-TLV MAY be optionally 
used when a leaf joins the PW 
  tree to announce to the source that it 
is part from the PW tree. If 
  this option is chosen, the Egress T-PE 
adds to the FEC Element this 
  TAII sub-TLV in the Label Map message. 
As soon as in the source 
  direction a Label Map is not required since 
for instance a S-PE 
  already maintains a state for this MS-PW tree, 
the information 
  related to the Leaf TAIIs is retrieved from the TAII 
Leaf sub-TLV and 
  is propagated by means of a LDP Notification message 
up to the 
  corresponding Ingress T-PE.   
> I am not sure 
about the propagation of TAII Leaf sub-TLV. Is it sent to ingress T-PE directly, 
or to the upstream S-PE(if there exists such S-PE in the upstream 
direction)?   
[FJ] The 
Notification message can not be directly sent to the Ingress T-PE if there is 
not direct T-LDP session to reach the Ingress T-PE, i.e. S-PE in between. That's 
the reason why the message should be propagated hop by hop (i.e. S-PE by 
S-PE) up to the 
Ingress T-PE. 
 I agree with 
you that's worth clarifying this section. 

Best Regards! 

Xinquan Zhang 

2009/4/15