Here is my early YANG doctors review of draft-ietf-ippm-on-path-telemetry-yang-00. There are some major issues that make it difficult to understand how this model is supposed to be used. I will do a more detailed review once these are addressed. First of all, the included tree diagram says that all nodes are config false, but in the data model all nodes are config true. (also, the names of the nodes in the tree diagram don't match the module in many cases). What is the intention? Should all nodes be config false? Including filters and node actions? The Security Considerations section seems to indicate that at least some nodes are config true. There is a global leaf "timestamp" which is described in the text as "the timestamp of the message". How can a global leaf contain a timestamp of "the message"? Most description statements contain basically no information. For example: leaf direct-export-data { type ioam-trace-data; description "This object indicates the direct export data."; } I suggest you expand the descriptions, and add references where applicable. Finally I suggest you add some examples in an appendix that show how this model can be used. /martin