Thanks Mahesh for your review. The authors would be back with an update and reply SOON. > -----Original Message----- > From: Pce [mailto:pce-bounces@xxxxxxxx] On Behalf Of Mahesh Jethanandani > Sent: 27 November 2018 08:29 > To: yang-doctors@xxxxxxxx > Cc: draft-ietf-pce-pcep-yang.all@xxxxxxxx; pce@xxxxxxxx; ietf@xxxxxxxx > Subject: [Pce] Yangdoctors early review of draft-ietf-pce-pcep-yang-08 > > Reviewer: Mahesh Jethanandani > Review result: On the Right Track > > Document reviewed: draft-ietf-pce-pcep-yang-08 > > I am not an expert in PCEP. This review is looking at the draft from a > YANG perspective. With that said, I have marked it as “On the Right Track” > because of some of the points discussed below. > > Summary: > > This document defines a YANG data model for the management of Path > Computation Element communications Protocol (PCEP) for communications > between a Path Computation Client (PCC) and a Path Computation Element > (PCE), or between two PCEs. The data model includes configuration data > and state data (status information and counters for the collection of > statistics). > > Comments: > > General > > - The module uses indentation that varies all over the module, from 2 > spaces to 5. Please fix the module to have consistent indentation. > > - The module makes heavy use of groupings. They are great if they are > being used in multiple places. But I seem to see single usage of > groupings, which makes the model hard to read. Please collapse all > groupings that are used only once into the module. > > Abstract: > > It is best not to try to redefine terms, specially if they have already > been defined already in another RFC. Case in point, "state data". This > term has been defined in RFC6241, and it would be best to list it in the > Terminology and Notation section, as has been done with other definitions. > > The following terms are defined in [RFC6241]: > > o configuration data > > o state data > > Introduction: > > Please update reference of YANG to RFC7950. These are YANG 1.1 modules > after all. > > Section 5. The Design of the PCEP Data Model. > > Thank you for first of all for creating a abridged version of the tree > diagram. > What would really help to understand the design of the model would be to > place the full tree diagram at the end of the section, and move sections > 5.3 to 5.7. > directly under 5.1. Scrolling through pages of the full diagram to get to > the design sections is painful to read. > > Section 10. PCEP YANG Modules > > - Please list all RFCs and I-D that are referenced in the model, so there > is a normative reference to them in the draft. > > - Please expand the reference to different RFCs to include the title of > the RFC, and not just the number. > > - The reference to tls-server and tls-client should be to I-D.ietf- > netconf-tls-client-server, as it is not an RFC as yet. Also, the document > refers to all other RFCs as RFC XXXX. What is the RFC editor supposed to > replace XXXX with? With the RFC number assigned to this draft?? I think > you want to refer to I-D that contain those modules. > > - What is "PCEP common"? That term has not been defined anywhere in the > document, but is used in the YANG model. > > - What is the 'identify pcep' for? > > - Why is pcep-admin-status a enum and not a boolean? Since YANG nodes are > hierarchical, there should be no reason to repeat prefixes like 'admin- > status' > in node names such as 'admin-status-up', both where it is defined and > where it is used (under admin-status). > > - Where are the different operational status definitions defined? Can that > RFC be referenced? Same for Session state, Association Type, Objective > Function. > > - Could the YANG module use existing definitions? For example could the > module use ospf-area as defined in I-D.ietf-ospf-yang or use isis-area > defined in the ISIS YANG Module. > > - Can the document use more descriptive names for features such as 'gco'. > > - If the range of the timer is 1..65535, why does it need to be a uint32? > Same for the range of 0..255. > > - RFC 5440 makes no reference to 'max-keep-alive-timer' or 'max-dead- > timer'. If they are max value, can they not be expressed as part of the > range for 'keep-alive-timer' or 'dead-timer'? Same for 'min-keep-alive- > timer' and 'min-dead-timer'. > > - What is the default value for 'admin-status'? > > - The grouping pce-scope seems to be defining a header with each of the > leafs as bits in the header. In that case, it would be better if this was > defined as a bits/bit field, rather than leafs that are of type uint8 and > boolean. Same for the grouping called 'capability' > > - The description "LSP is PCE-initiated or not" is hardly a description > for the leaf 'enabled'. It might be more a description of the feature > 'pce-initiated'. > > - Could description "Valid at PCC" be improved upon? > > - Most keys are defined as 'type binary'. Why is key-string defined as > 'type string' or 'type hex-string', and not 'type binary'? Is it possible > to reuse definitions from draft-ietf-netconf-crypto-types? > > - I am not an expert in this protocol, but a lot of the nodes defined are > generated by the system. Yet, they are defined as rw. For example, the > list 'path-keys' carries a description "The list of path-keys generated by > the PCE". > If so, should this not be marked 'config false'. I would suggest authors > take a more concerted look and see what nodes are indeed rw and which ones > are ro. > Other examples include 'req-id' and 'retrieved'. > > - Can this error-message and description be reconciled? > > error-message > "The Path-key should be retreived"; > description > "When Path-Key has been retreived"; > > - It is great to see that extensive amount of statistics are required to > be implemented by the model. How many implementations actually support all > these statistics? What would happen if implementations support a small > number of these statistics? In other words, are all these statistics > required to be maintained/implemented? > > - In addition, a lot of the statistics have when statements. Since these > are statistics maintained by the system, why the when statement? Does it > mean that even if the statistics are written by the system, they are not > valid (for > reading) under certain scenarios. Or is it more likely that they are only > written when the role is ether of a 'pce' or 'pcc-and-pce', in which case > reading for other roles would return 0 values. > > _______________________________________________ > Pce mailing list > Pce@xxxxxxxx > https://www.ietf.org/mailman/listinfo/pce
