Re: [Teas] A New I-D on PCE as a central controller

As I said, I specifically wonder about Section 3.2.3 "Service Delivery", which states (omitting some parts that are not relevant here):

"Various network services may be offered over a network. These include protection services [...] Virtual Private Network (VPN) service (such as Layer 3 VPNs [RFC4364] or Ethernet VPNs [RFC7432]), or Pseudowires [RFC3985]. [...]  A PCE-based central control can consider the whole network and all components of a service at once when planning how to deliver the service. It can then use PCEP to manage the network resources and to install the necessary associations between those resources."

This wording on use of PCEP confuses me, no matter what interface we talk about. I would have assumed that YANG-based protocols such as NETCONF/RESTCONF could be useful in this context, and I am a bit surprised that the document focuses on using PCEP e.g. for L3VPN service delivery. By the way, I also wonder how PCEP fits into the discussion on QoS classification in Section 3.2.2.

I wonder if the authors could add to Section 3.2.2 and Section 3.2.3 e.g. a message sequence chart that illustrates how what is discussed in those sections relates to PCEP?

Michael

-----Original Message-----
From: Teas [mailto:teas-bounces@ietf.org] On Behalf Of EXT Adrian Farrel
Sent: Friday, May 13, 2016 6:54 PM
To: Scharf, Michael (Nokia - DE); teas@ietf.org
Subject: Re: [Teas] A New I-D on PCE as a central controller

Hello again, Michael, it seems to be my day for replying to your emails.

> When reading about uses cases such as L3VPN service delivery in 
> "Section
3.2.3",
> what is the author's view on the line of demarcation between NETCONF 
> and PCEP?

Well, I wonder which interface you're talking about.
The ones that out in here are:
- the interface between customer and operator
- the interface between "service orchestrator" and "network orchestrator"

The former of these is like the interface used in L3SM. As co-chair of L3SM, you might not be surprised to hear that my view is that NETCONF is a fine solution - well, the use of a YANG data model, in any case.

The latter is the interface between "Orchestrator / Service Manager / OSS / NMS"
and "PCE-based Controller" as shown on the various figures in the picture. We haven't discussed this interface in the document, and perhaps we should.

If you look at Figure 6 (with the hierarchy of controllers) you might observe that the parent controller could be implemented to act as though it is talking to an NE (in the abstract node model) and that means that the southbound interface of the parent controller would be PCEP. That means (of course) that the northbound interface of the child controller would also be PCEP. Then, it might seem obvious that we would want all PCE implementations to behave the same way and so that makes the northbound interface of the parent PCE would/could/should/might also be PCEP.

What do you think?

Thanks,
Adrian

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