[Lime] Alia Atlas' Discuss on draft-ietf-lime-yang-connectionless-oam-14: (with DISCUSS and COMMENT)

[Alia Atlas <[e-mail]>]

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draft-ietf-lime-yang-connectionless-oam-14: Discuss

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DISCUSS:
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Thank you for your work on this document.  I have a number of serious concerns
- but they all amount to fixing up your references and slight restructuring 
for clarity and reuse.

1) In Sec 3.1, the reference is system-id to represent the device or 
node.[I-D.ietf-spring-sr-yang] I believe that should be "typedef router-id {
       type yang:dotted-quad;
       description
         "A 32-bit number in the dotted quad format assigned to each
          router. This number uniquely identifies the router within
          an Autonomous System.";
     }"
from draft-ietf-rtgwg-routing-types.
Certainly "[I-D.ietf-spring-sr-yang]" is NOT an informative reference with such
a dependency.

I see that this document actually redefines router-id, instead of using it as
part of the included import from
 import ietf-routing-types {
   prefix rt;
  }
On p.27, I see "leaf system-id {
          type rt:router-id;
          description
            "System ID assigned to this node.";
        }"
so it is using the routing-yang-types, but renaming it as system-id, there.
Consistency isn't just the hobgoblin of little minds - it's actually useful.

In choice to-location, again "case system-id {
          leaf system-id-location {
            type router-id;
            description
              "System id location";
          }

          description
            "System ID";"
using the locally defined router-id and renaming it instead of using
rt:router-id.

2) On p. 13 & 14, there are many identities associated with time and
time-stamps.  I cannot believe that the best way to handle these is by having
them as part of an OAM model!   At a minimum, they should be defined as a
separate module and then included, even if it is in the same draft.  Then they
will be available for reuse elsewhere.

3) This is extending [I-D.ietf-i2rs-yang-network-topo] - I do not believe this
should be merely an informative reference.

4) I cannot tell if I-D.ietf-rtgwg-ni-model is informative or normative; it is
not referenced in the draft - though there are fields that are labeled NI
without adequate description.

5) [I-D.ietf-rtgwg-routing-types] is not an informative reference.  Its module
is imported and used.  It must be normative.

6) [I-D.ietf-spring-sr-yang] is listed as an informative reference, but if it
were actually used as described, it would need to be normative. Instead, I
believe this can be removed as a reference.


----------------------------------------------------------------------
COMMENT:
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a) Sec 3.8: It is unfortunate that the cc-session-statistics-data structure is
not a list of {traffic type, cc-session-statistics} instead of hardcoded
members for IPv4 and IPv6 traffic only.  While it can still be extended for
additional traffic types, the naming may be inconsistent and there's no
requirement that the contents are cc-session-statistics.

b) On p.9: " +--:(system-id)
      |                 +--rw system-id-location?      router-id"

Why isn't this just named router-id instead of system-id, for consistency? 
This comment applies throughout the draft.

c) The use of "tp" to mean test-point is a bit unfortunate in a model that is
building off of the network topology one, which uses "tp" for termination-point.

d) On p. 13: "identity address-attribute-types {
    description
      "This is base identity of address
       attribute types which are ip-prefix,
       bgp, tunnel, pwe3, vpls, etc.";
  }"

I haven't a clue what is meant by a bgp address attribute type or a tunnel one.
 Can you please expand the description to be substantially more meaningful? 
How is it used?

On p. 24, I see these defined
" case bgp {
            leaf bgp {
              type inet:ip-prefix;
              description
                "BGP Labeled Prefix ";
            }
          }
          case tunnel {

            leaf tunnel-interface {
              type uint32;
              description
                "VPN Prefix ";
            }
          }
          case pw {
            leaf remote-pe-address {
              type inet:ip-address;
              description
                "Remote pe address.";
            }
"
but unlike the other cases with clear descriptions and references to the
relevant RFCs, these are NOT clear and do not even fully expand acronyms.

e) "grouping tp-address-ni "  Please expand what NI is the abbreviation for in
the description.