Subject: [Iotops] Comments on virtualizing PLC

From: Kiran M <[email-masked]>
Date: Thu, 24 Mar 2022 12:49:25 -0700

Hi all,
I realized my responses to the comments could have been  better:

1. Henk's: on the volume of work involved:
     IMHO,  this is due to missing pieces such as a common reference 
framework or a model for such conversations. The document highlights 
problems from an operator's view, i.e. "what will it take to realize 
virtual PLCs?" This does not mean that IETF solutions are not available 
already, had hinted at SFC & Detnet possibilities. The next step would 
be to show how these methods apply and where the potential gaps are? 
More converged the IT/OT get, higher the likelihood of using protocols 
developed here.

I mentioned common interface between virtual PLC and I/O was the place 
to solve the problem of many protocol formats.

2. On detnet status:
I should clarify that I meant to say Detnet connects (not over) TSNs.  
It could be used for edge to factory site connectivity. Detnet dataplane 
is in RFCs 9024, 9025, 9037. More importantly, the document's focus is 
on other aspects of industrial networking and would reuse Detnet when 
possible.

3. On vendor PLCs:
The document did not dwell in to commodity hardware, it's focus is on 
abstraction and dis-aggregation. Same vendors could utilize standard 
methods with their own platforms to start with.

Even though there is specific interest on converging OT protocols, 
background context should be established too. Therefore, it will be 
useful to have an active discussion here on the list.

Cheers,
Kiran