Hi Dave, Good questions. Let me see if I can answer some of them. For perspective, I have not been involved in the developoment of any of the proposed technical directions, but I have been a general technical commentator with 16 years of IETF NM experience ;-) > -----Original Message----- > From: ietf-bounces@xxxxxxxx [mailto:ietf-bounces@xxxxxxxx] On > Behalf Of Dave Crocker > Sent: Wednesday, April 23, 2008 12:04 AM > To: Eric Rescorla > Cc: iesg@xxxxxxxx; ietf@xxxxxxxx > Subject: Re: WG Review: NETCONF Data Modeling Language (netmod) > > > > Eric Rescorla wrote: > > Which is why it is now returned to the broader community for > > additional perspectives from those not already committed to a > > particular path Dave, my impression of your questions is that "they" means the "broader community" - those not already committed to a particular path - that EKR references. I will answer your questions from that perspective. > > > Are they committed to doing the work? I believe the answer to this is yes. The Netconf community raised the potential need for a new data modeling language because XSD was too human-unfriendly, and both XSD and RNG lacked features needed for network management purposes. We have performed multiple comparison exercises between XSD and RNG (e.g., modeling Diffserv configuration), and all have fallen somewhat short in terms of expressing the things the OPS area feels are important to express, based on 20 years of experience with SNMP and SNMPCONF and COPS-PR, and based on experience with CLI-based configuration, and operator feedback about configuration requirements exprsessed during the IAB Network Management Workshop in 2002 an dthe subsequent "world tour" of NANOG, RIPE, and other operators' groups. People from the broader community (especially the APPS area) with experience in XSD and RNG came forth and prepared multiple concrete proposals to compare data modeling language approaches. All of these previous efforts have tried to be inclusive of the broader community, but many have been unofficial meetings, so the broader community may have been under-represented in some of these comparisons, but XSD and RNG have been prominent proposals. After multiple comparisons, the rough consensus of those involved was that the results remained human-unfriendly, especially the XSD format, and efforts at producing XSD schemas in WG documents had real difficulties producing valid XSD. While RNG was more human-friendly, it still was less human-friendly than desired. Unfortunately, despite going to this effort, the CANMOD BOF was prevented from actually comparing the various concrete proposals (the "beauty contest"), which would have shown XSD versus RNG versus YANG, relative to the stated requirements for network management purposes. > > Do they have their own constituency? > The supporters of XSD have their own constituency. The supporters of RNG have their own constituency. The supporters of the YANG proposal have their constituency. And there are constituencies for other proposals that have not been widely accepted. Folowing a proposal for a BOF, the APPS area and some IAB members wanted some extra input on the need for a data modeling language. A design team composed of members of the OPS community and the APPS community was created to document a set of requirements. The OPS community had already been through this exercise multiple times already, as documented in multiple existing RFCs on requirementsa for configuration, and new requirements were allowed to be added to the existing requirmeents by represntatives of the various consistuencies. It was decided by the OPS ADs that concrete proposals should be prepared for presentation and comparison at a BOF to compare alternatice approaches. Multiple proposals were prepared, including proposals from OPS area and APPS area people. These proposals were prepared for a "beauty contest" becauser there was strong aoncensus amongst the various constituencies that we needed a data modeling language, and some felt that the existing XML-based schema languages might be sufficient. The proposals, however, reflected the fact that the existing languages fell short when trying to represent information necessary for network management **based on operator input**. Existing XML-based tools would be unable to validate the data models without having specfic extensions provided through annotations, and requiring modifications to existing tools to process those annotations. At the CANMOD BOF, the "beauty contest" between proposals was not allowed to be held, because certain members of the "broader community" insisted that the question of whether the existing languages could suffice be discussed even further, even though there was strong consensus from the OPS community (and recently from the APPS community) that the existing schema languages fall short of the requirements for network management data modeling. Following the CANMOD BOF, the constituencies from the OPS and APPS areas came together at the OPS Open area meeting and at the OPS/IESG breakout meetings to discuss a way forward, and the various constituencies reached agreement that YANG provoded a reasonable human-friendly language, and a translation to either XSD or RNG would meet the needs for a machine-friendly language suitable for XML-based tools. Consensus of these constituencies was that RNG + Schematron (i.e., DSDL) provided better capabilities for validation of the network management specific requirements than XSD alone or RNG alone. The consensus of the these constituencies was also that YANG was more human-friendly then either XSD or RNG or DSDL. So constituencies of the "broader community" have been very active in establishing the proposed direction, in crafting the proposed charter, and have committed to working on the documents identified in the proposed charter. > Since the topic is not new, where have they been and why have > they not > developed their own group consensus? This topic is not new, and constituencies of the "broader community" have been active in establishing the proposed direction, and the proposed charter, and have committed to working on the documents identified in the proposed charter. > > Rather than "perspectives" where are the technical concerns > that Bert asked about? > > d/ > -- > > Dave Crocker > Brandenburg InternetWorking > bbiw.net > _______________________________________________ > IETF mailing list > IETF@xxxxxxxx > https://www.ietf.org/mailman/listinfo/ietf > David Harrington dbharrington@xxxxxxxxxxx ietfdbh@xxxxxxxxxxx dharrington@xxxxxxxxxx _______________________________________________ IETF mailing list IETF@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf