Subject: [Bier] PCE Controller & SDN Controller & Netconf/Yang NMS Controller - lines blurred and can the names be used ubiquitously meaning the same

From: Gyan Mishra <[email-masked]>
Date: Sat, 10 Oct 2020 15:26:56 -0400

Dear TEAS, PCE, IDR, LSR, BESS, BIER  Spring Working Groups,

I have noticed that after reviewing many drafts across many WGs it seems in
the industry that the lines seem to be blurred between a PCE controller,
ODL or Openflow SDN Controller and a Netconf/Yang NMS Controller ZTP & Day
X provisioning.

As this is a software sitting on a server you can have a swiss army knife
server that does everything from PCE path computation to  Netconf/Yang ZTP
& Day N provisioning as well as any SDN Controller ODL or Openflow
controller type functions as well.

How this comes into play and realization of the lines being blurred is the
use of BGP-LS in building the IGP topological graph of the network which
was designed for PCEP and PCE & PCC active & passive off line path
computation for both RSVP-TE or SR-TE path instantiation.

However now BGP-LS can also be used for other functions now such as usage
as I am a Shepherd reviewing a draft for BGP-LS usage for BIER to use
BGP-LS to gather the elements internals within BIER using the same BGP-LS
data structures to populate with BIER specific information to graph the
BIER topology.  So here we are not doing any path computations as we are
using in this use case  for NMS type function to gather data for ZTP & Day
N provisioning.

Similarly other use cases such as with TEAS TS-Transport slice and being
able to provision TS and capturing the TS Enhanced VPN RT & resource
information and leveraging BGP-LS to do the same data gathering & ZTP like
controller style provisioning.

It does seem as though BGP-LS as its a means of "data gathering" "dump
truck" of anything with the kitchen sink included to build any type of
topological graph of literally anything under the sun.  I see that is a
nice to leverage but it does in fact blur the lines of NMS Netconf/Yang
Controller based functionality and  PCE path computation functionality and
SDN controller based ZTP functionality into a single ubiquitous server that
can do all of the above and use BGP-LS to accomplish the "kitchen sink"
tasks.  It does however transform BGP to be an NMS tool but a "tool" and
not just the original function which it was intended NLRI network
reachability.

Am I off base and please let me know as its BGP-LS is being way over
leveraged.  There are pros & cons to everything but I thought I would bring
up to the WG as an important discussion point.

Lots of food for thought.  Welcome all comments as well as concerns related
to this topic.

Kind Regards,

<http://www.verizon.com/>

*Gyan Mishra*

*Network Solutions A**rchitect *

*M 301 502-134713101 Columbia Pike *Silver Spring, MD

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From: Gyan Mishra <[email-masked]>
Date: Tue, 13 Oct 2020 00:33:50 -0400

All

Another way of looking at BGP-LS is that it is an extremely powerful tool
for centralized controller based architectures or hybrid architectures, and
it does not bog down or impact the agility and lightweight aspects of BGP,
as BGP has its overall ability to stack & pile on SAFI's and codepoint's as
necessary to meet the desired design objectives.  So BGP can still remain
as light weight or as heavy weight as desired based on the design objective.

! BGP LS IAIA codepoints
https://www.iana.org/assignments/bgp-ls-parameters/bgp-ls-parameters.xhtml

So its safe to say that the use cases are pretty limitless for BGP-LS from
PCE path instantiation to ZTP & Day X provisioning & configuration.  I
think "dump drunk" depiction of BGP-LS is really a negative perception, as
BGP-LS has the native data structures primitives to build customizable
TLV's to meet almost any design objective.

Comments welcome.

Kind Regards

Gyan

On Sat, Oct 10, 2020 at 3:26 PM Gyan Mishra <[email-masked]> wrote:

> I have noticed that after reviewing many drafts across many WGs it seems
> in the industry that the lines seem to be blurred between a PCE controller,
> Lots of food for thought.  Welcome all comments as well as concerns
> related to this topic.
>
> Kind Regards,
>

-- 

*Gyan Mishra*