Med Rev08 #9 YANG service-slos

[lana-wu]

grouping service-slos {
       description
         "Directly measurable objectives of a Slice Service.";
       container slo-policy {
         description
           "Contains the SLO policy.";
         list metric-bound {
           key "metric-type";
           description
             "List of Slice Service metric bounds.";
           leaf metric-type {
             type identityref {
               base service-slo-metric-type;
             }
             description
               "Identifies an entry in the list of metric type
                bounds for the Slice Service.";
           }
           leaf metric-unit {
             type string;
             mandatory true;
             description
               "The metric unit of the parameter. For example,
                s, ms, ns, and so on."; 
           } 
           leaf value-description {
             type string;
             description
               "The description of the provided value.";
           }
           leaf percentile-value {
             type percentile;
             description
               "The percentile value of the metric type.";
           }
           leaf bound {
             type uint64;
             default "0"; 
             description
               "The bound on the Slice Service connection metric.
                When set to zero, this indicates an unbounded
                upper limit for the specific metric-type.";
           }
         }
         leaf availability {
           type identityref {
             base availability-type;
           }
           description
             "Service availability level";
         }

Med:
"metric-unit": What if the unit does not comply with the metric type? Ex. delay + unit=byte or mbps? Why not defining those as identyrefs?
"bound" default: Do you really need this. Please note that FC8407 says:
"The following guidelines apply to reusable groupings, in order to make them as robust as possible: ...
Do not include a "default" substatement on a leaf or choice unless the value applies on all possible contexts."

[lana-wu]

"metric-type" includes bandwidth, delay, packet loss, and jitter. Then "metric-unit" should cover time unit, bandwith unit, and packet loss rate, will YANG identity is too restricted?