IETF Last Call Review of draft-ietf-ccamp-wdm-tunnel-yang-03
review-ietf-ccamp-wdm-tunnel-yang-03-rtgdir-lc-hares-2025-04-04-00

This is an early review for the RTG-DIR.

Status: Document is basically sounds and with both configuration and monitoring
features for the WSDON and Flexi networks

Some editions would help the yang module readability:
1. Comments on draft that contains imported modules (ietf-te,
ietf-layer0-types, ietf-yang-types)

2. The references have problems since:
a. the above dependent modules are not mentioned
b. The yang tree description model  (RFC8340) is not mentioned

3. One augment seems odd in the yang diagram:
     augment /te:te/te:tunnels/te:tunnel/te:primary-paths
             /te:primary-path/te:explicit-route-objects
             /te:route-object-exclude-always/te:type
             /te:numbered-node-hop/te:numbered-node-hop:

  It would seem natural to have
          …./te:numbered-node-hops:/te-numbered-node-hop.
             Rather than
           /te:numbered-node-hop/te:numbered-node-hop:

I am having trouble tracking this down in the yang module.

Andy Bierman has reviewed this model, so perhaps it is ok.  It just seems odd.

5) The (multi) structures under grid-type for super-channels

A second set of structures that are not easy to check are the (multi) structure
below. My reading of the RFC8340 would indicate that (multi) – is the result of
a choice (single or super channel) where the super-channel has a list of
types:dwdm-n. (   RFC88340 *  for a leaf-list or list).

The data structure is reasonable.  However, I’ve not seen a list of configured
identity types in yang before. I am assuming that Andy Bierman (Yang Doctor)
looked at this issue.

          +--rw (grid-type)?
             +--:(fixed-dwdm)
             |  +--rw (fixed-single-or-super-channel)?
             |     +--:(single)
             |     |  +--rw dwdm-n?               l0-types:dwdm-n
             |     +--:(multi)
             |        +--rw subcarrier-dwdm-n*    l0-types:dwdm-n

Is it appropriate to a list of types?

Give time allows, I will send in a second review to the RTG-DIR chairs after a
deep dive into the model. I suspect that a deep dive has been done by Andy
Bierman.