[IPFIX] RFC 6728: Observation Point ID definition

[Marta Seda <[e-mail]>]

Hello,

RFC 6728 defines the observation point as the "location for which packets are observed".  RFC 6727 page 4.1 shows this uml relationship:

         +-------------------------------+
         | ObservationPoint              |
         +-------------------------------+
         | name                          |
         | observationPointId {readOnly} |
         | observationDomainId           | 0..*
         | ifName[0..*]                  |-------------+
         | ifIndex[0..*]                 |             | 0..*
         | entPhysicalName[0..*]         |             V
         | entPhysicalIndex[0..*]        |    +------------------+
         | direction = "both"            |    | SelectionProcess |
         +-------------------------------+    +------------------+


In RFC 6728, the observationpointid, ifname, ifindex,entphysicalname and entphysicalindex are part of the observationpointparameters grouping.

RFC 6728 has examples centered around the idea of creating a metering process that samples packets and reports statistics over ipfix (netflow-like statistics).

There is yang models that configure statistic collection.   It seems in that case (if you want to use ipfix to carry those statistics), that the observation point could refer to those entities (leaf-ref) that are already collecting statistics.  When I look at the RFC 6728 yang structure it seems there is an "attempt" to do that via the use of IfName, IfIndex, EntPhysicalName and EntPhysicalIndex (which are SNMP physical entities).  However you have logical entities that the current structure doesn't permit you to define as the observation points.  Is that a correct interpretation of the current yang for ipfix?  How can you refer to logical entities? (it seems the only place you could do this was to stick the leaf-ref into the name but not a good yang practice).

Please advise.

Thanks.

Marta Seda