Hi Ladislav, Thank you! We are working on a new revision that incorporates your comments. My answers inline tagged as [GF]. Best Regards, Giuseppe -----Messaggio originale----- Da: Ladislav Lhotka [mailto:lhotka@xxxxxx] Inviato: lunedì 26 febbraio 2018 13:35 A: yang-doctors@xxxxxxxx Cc: l2sm@xxxxxxxx; ietf@xxxxxxxx; draft-ietf-l2sm-l2vpn-service-model.all@xxxxxxxx Oggetto: Yangdoctors early review of draft-ietf-l2sm-l2vpn-service-model-08 Reviewer: Ladislav Lhotka Review result: Ready with Issues **** General comments - The 'ietf-l2vpn-svc' module contained in this document is rather large: it defines 386 schema nodes, 35 features and 175 identities. It is therefore natural to ask whether the authors considered splitting the definitions into multiple modules. This would make the data model more modular and probably also make some of the features unnecessary. See also draft-ietf-netmod-rfc6087bis-18, sec. 4.17. [GF]: Ok, Thanks for the suggestion. We will remove unnecessary identities, features. Note that unlike network element model, service model will describe various aspects of network infrastructure, including devices and their subsystems, and relevant protocols operating at the link and network layers across multiple device. So it is intentional to have such model design. - The module defines most containers, lists and even individual leaves in a grouping that is then used only once. This approach has its pros nad cons but it is not the common practice in YANG modelling - groupings are mostly defined only if they are used (or expected to be used) repeatedly and/or in different modules. [GF]: It is expected some of these groupings can be reused in some other external modules, or model extension. - Some of the groupings (e.g. 'site-device') reference nodes outside the grouping, which is discouraged, see draft-ietf-netmod-rfc6087bis-18, sec. 4.13. [GF]: Will fix it. Thanks. - Names are sometimes overloaded in that the same name is used for different purposes. For example, 'cloud-access' is used as the name of both a list and a feature. In one case ('bum-frame-delivery'), the same name is used for a list, the container that encloses it, and the grouping in which the container is defined. This should be avoided. [GF]: Ok **** Specific comments - Most when expressions correctly use the XPath function 'derived-from-or-self()'. In two cases ('vpn-id' and 'cos-id' leaves) identities are compared in XPath expressions using plain string equality. These XPath expressions need to be changed to use 'derived-from-or-self()' as well. [GF]: Ok - The when expression for container 'devices' user a disjunction of two 'derived-from-or-self()' checks. This usually indicates that a new identity can be defined from which both or-ed identities are derived. [GF]: Ok **** Instance examples The example instance documents contained in the document require to be carefully checked because they are often invalid or even not well-formed. I would also suggest to use examples in JSON encoding that is easier to read: The problems that I discovered include: - extra space in opening and closing XML tags < network-access-id> and </ network-access-id> [GF]: Will fix it. - p. 28: wrong namespace URI "urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc" [GF]: Will fix it. - p. 28: in the first 'vpn-service' entry (key 'VPNB'), two mandatory leaves are missing: 'ce-vlan-preservation' and 'ce-vlan-cos-perservation'. [GF]: Will fix it. **** Nits - The name of 'ce-vlan-cos-perservation' should most likely be 'ce-vlan-cos-preservation' [GF]: Will fix it. - Inconsistent indentation: features 'cfm' and 'y-1731' have less spaces of indentation than other features [GF]: Will fix it. - When concatenating literal strings, the widely accepted convention is to put the '+' sign ot the second line, and align the string components. That is, instead of path "/l2vpn-svc/vpn-profiles/valid-provider-identifiers"+ "/cloud-identifier/id"; use path "/l2vpn-svc/vpn-profiles/valid-provider-identifiers" + "/cloud-identifier/id"; [GF]: Will fix it. Questo messaggio e i suoi allegati sono indirizzati esclusivamente alle persone indicate. La diffusione, copia o qualsiasi altra azione derivante dalla conoscenza di queste informazioni sono rigorosamente vietate. Qualora abbiate ricevuto questo documento per errore siete cortesemente pregati di darne immediata comunicazione al mittente e di provvedere alla sua distruzione, Grazie. This e-mail and any attachments is confidential and may contain privileged information intended for the addressee(s) only. Dissemination, copying, printing or use by anybody else is unauthorised. If you are not the intended recipient, please delete this message and any attachments and advise the sender by return e-mail, Thanks. Rispetta l'ambiente. Non stampare questa mail se non è necessario.
