Re: [Pce] draft-dhodylee-pce-pcep-ls next steps!

Adrian Farrel <> Sun, 18 July 2021 18:40 UTC

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From: "Adrian Farrel" <>
To: "'Gyan Mishra'" <>, "'Dhruv Dhody'" <>, <>, "'pce-chairs'" <>, <>
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Date: Sun, 18 Jul 2021 19:40:12 +0100
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Subject: Re: [Pce] draft-dhodylee-pce-pcep-ls next steps!
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Hi Gyan,


I am very much in favour of positioning this work as Experimental. 


It is important (as with all IETF Experiments) to capture:

-          What stops this extension “escaping" in the Internet?

-          What stops this experiment clashing with other work or harming deployed equipment? 

-          How will you judge the success or failure of the experiment, and when? 

-          What follow-up to the experiment do you propose?





From: Gyan Mishra <> 
Sent: 05 July 2021 07:43
To: Adrian Farrel <>uk>; Dhruv Dhody <>om>;; pce-chairs <>rg>;
Subject: draft-dhodylee-pce-pcep-ls next steps!



Dear PCE WG,


We presented the PCEP-LS [1] I-D [2] in the IETF 110 with a quick recap and a summary of past discussions. Some new scenarios such as PCECC, H-PCE were highlighted where the PCEP session could be reused. 


This is an experimental I-D with the aim to progress research and development efforts. This work is not a replacement for any of the existing mechanisms. There are specific scenarios highlighted where the reuse of PCEP sessions for this information is deemed useful. To make progress, it may not be useful to rehash the beauty context between everyone's favorite protocol :). What would be useful would be - finding out if there is still interest in this experimental work by some in the WG; are there strong technical objections for the experiment in its limited scope etc... 


As a next step, it would be good to define the scope of the experiments and expected output especially targeting the scalability concerns as well as impact in other protocols and the network, etc.   


>From the last query on this draft March 18th we received positive feedback from Aijun Wang with China Telecom mentioned that as a telco are interest in deploying in their network PCEP-LS once the Huawei implementation is ready.  Aijun pointed out in the thread that using this draft simplifies the implementation of SDN controller.  One question asked by Aijun was related to section 9.2.1 LS Capability TLV R=1 remote allowed meaning hybrid mode to provide flexibility for operators not yet using SDN (SDN-like) SBI.  For any operators already using PCEP as SDN (SDN-like) SBI, a direct PCEP session already exist between all the nodes in the network and the PCE which would be the PCECV SDN scenario in which case the R flag in the open message is set to 0.  


We also received positive feedback from Peter Park with telco KT regarding interest in PCEP-LS.


We also had feedback from Bin as they have implemented PCEP and have interest in this experimental implementation of this work.


I would like to poll the WG again for interest in progressing research and development efforts of this draft as experimental.  


As stated in the last WG poll, I would like get feedback from the WG on scope of experiments especially related to scalability concerns and impact to other protocols on the network.



Gyan (on behalf of co-authors)







Gyan Mishra

Network Solutions Architect 

Email <> 

M 301 502-1347




Gyan Mishra

Network Solutions Architect 

Email <> 

M 301 502-1347