Clarification on LSA Definitions

[Ryan1905]

G'day

I'm in the process of developing a HLD for a potential NSO deployment. While reading the LSA documentation on the Developer website, I came across the terms CFS and RFS. From what I understand:

- The upper layer (CFS) is customer-facing and can provide northbound connectivity for external programs and processes. Along with this, it manages the communications from an external source and pushes the required changes down to the relevant RFS nodes.

- The lower layer (RFS) is resource-facing and manages the configuration for attached devices.

Two things I would like clarified are:

1) Is my understanding of the CFS and RFS correct? If not, where can I find more information as I can't see too much in the existing documentation.

2) Since the RFS manages configuration for each connected device, does the CDB on the CFS maintain the configuration from all RFS's?

I'm still quite new to NSO and really enjoying the work I'm doing at the moment. I'll be looking at doing some formal NSO training later on in the year to recertify my CCNP Enterprise certification.

Thank you, and I look forward to learning more and contributing to the NSO community.

[vleijon · Accepted solution]

1. Your understanding is correct. It might be good to note that while CFS/RFS are good terms that may help you align to a good architecture NSO doesn’t have any built in understanding of the concepts, for NSO it is merely an upper and a lower layer and you can divide things any way you want. In many cases the “true” CFS is in an upper layer OSS or BSS system.
2. The CDB on the upper layer contains most of the configuration of the lower layer NSO. It does _not_ contain the device config from the lower layer and you can modify the LSA NED to further limit what you can see on the upper node.

The example examples.ncs/getting-started/developing-with-ncs/22-lsa-single-versio-deployment is an easy way to just start an example and check what is visible and what operations are available.

[Ryan1905]

G'day @vleijon,

Thank you for your reply.

It's good to know that my understanding of the CFS/RFS concepts is correct. Once I get my NSO instances going again, I will check out the example and go from there.