I am the assigned Gen-ART reviewer for this draft. For background on Gen-ART, please see the FAQ at < http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>. Please resolve these comments along with any other Last Call comments you may receive. Document: draft-ietf-mpls-tp-te-mib-09.txt Reviewer: Elwyn Davies Review Date: 10 December 2014 IETF LC End Date: 8 December 2014 IESG Telechat date: (if known) - Summary: Not ready. I am not a MIB expert nor an MPLS(-TP) configuration expert, so I have assumed that the details of the MIB specification have been addressed by Joan's MIB Doctor review and the configuration examples have been checked by an MPLS-TP expert. However, the introductory text needs significant work to make it easier for people who are not MPLS-TP experts to come to grips with the document. The major issue with this document is that it appears to go against the current IETF view that SNMP is not a satisfactory solution for configuring networks. The document has effectively reiterated the RFC 3812 situation from 10 years ago when the IETF held its nose and said that SNMP was the only game in town even if security sucked. As I mention below, this was extensively discussed a year ago but I couldn't determine whether this draft was given a special dispensation even though consensus seemed to be that writeable MIBs were considered inappropriate. If this is the case, it will be sufficient to adapt the end of s1. AFAICS this draft has not had the 'grammar review' recommended by its AD about a year ago and there are a number of areas in the object descriptions where language improvements would be desirable in addition to notes given here. That is it still needs the grammar review. There are some more minor issues, particularly as regards the description of the types of tunnel in s1, the discussion of the contents of the MIBs in s6 and possibly in regard to the interaction with the standard interface table. Major issues: Support for configuration: The issue of SNMPset (write) support was discussed at length in the context of the MIB doctors' review of v-05 of this draft. The consensus at that time appeared to be that provision of write support in new MIBs should be strongly discouraged. I am unclear what the outcome of that discussion in the context of this draft was, but it is clear that the draft is very much written from the point of using the MIB as a configuration tool, especially in s9 (examples of usage). Whilst this technique reflects the equivalent section is RFC 3813, that document was written over 10 years ago and considerable effort has been devoted to providing alternative and more secure ways of configuring networks in the intervening time. The body of the document has not been altered to reflect the discussion that occurred. "Lip service" is paid to the discouragement of the use of SNMPset by the addition of para 3 of s1: It is understood that SNMP SET is not used for MPLS configuration these days, however the read-write and read-create option is still specified for some objects as a way to provide the information model. It is not clear to me why providing read-write or read-create options enhance the MIB or are "a way to provide the information model". I note that despite the extensive discussion of this topic by WG members and MIB specialists back in December 2013, this issue was not flagged up in the Shepherd's write up. If it has now been agreed that the configuration "flavour" is to be accepted as WG consensus in spite of being contrary to current practice, it appears to me that the word "configuration" should be removed from the last sentence of para 2 of s1 and the last para of s1 rewritten to explain why write capabilities are used in a more convincing manner. Minor issues: Abstract/s1: Needs to be clear in both places that is is intended for MPLS-TP, this: -- Abstract and s1: s/transport networks./MPLS networks conforming to the MPLS Transport Profile (MPLS-TP)./ s1: What is a Non-MPLS-TP (transport) network? s1: The explanation of what the MIB extensions in this document actually do is not clear to the general reader. I suggest replacing para 2 completely: OLD: The existing MPLS Traffic Engineering (TE) Management Information Base (MIB) [RFC3812] and Generalized Multiprotocol Label Switching (GMPLS) Traffic Engineering Management Information Base [RFC4802] do not support the management of transport network requirements of Tunnel end points with non-IP based identifiers and static bidirectional tunnels. This document focuses on static bidirectional MIB modules that should be used in conjunction with [RFC3812] and companion document [RFC3813] for MPLS Transport Profile (MPLS-TP) path configuration and management. NEW: As described in the MPLS Traffic Engineering (TE) Management Information Base (MIB) definition [RFC3812], MPLS traffic engineering is concerned with the creation and management of MPLS tunnels. This term is a shorthand for a combination of one or one or explicitly routed LSPs (ERLSPs) linking an ingress and an egress LSR. Several types of point-to-point MPLS tunnels may be constructed between a pair of LSRs A and B: - Unidirectional with a single LSP (say) from A to B. - Associated bidirectional consisting of two separately routed ERLSPs, one linking A to B and the other linking B to A. Together the pair provide a single logical bidirectional transport path. - Corouted bidirectional consisting of an associated bidirectional tunnel but with the second ERLSP from B to A following the reverse of the path of the ERLSP from A to B, in terms of both nodes and links. Tunnels may be either statically configured by management action or dynamically created using a LSP management protocol. The existing MPLS TE MIB [RFC3812] and the Generalized Multiprotocol Label Switching (GMPLS) Traffic Engineering Management Information Base [RFC4802] address only a subset of the combinations of statically and dynamically configured tunnel types, catering for statically configured unidirectional tunnels together with dynamically configured unidirectional and corouted bidirectional tunnels. They are alsorestricted to to end point LSRs identified by IP addresses. The MPLS-TP TE MIB defined in this document extends the MIB defined in [RFC3812] to cover all six combinations (that is adding support for statically configured associated and corouted bidirectional plus dynamically configured associated bidirectional tunnels). It also extends support to end points that are identified other than with IP addresses. This support is provided by a suite of four MIB modules that are to be used in conjunction with the MIBS defined in [RFC3812] and the companion document [RFC3813] for MPLS Transport Profile (MPLS-TP) TE path [configuration and]* management. END NEW * Note: Using the term 'configuration' is inconsistent with the discussion in para 3. See Major Issues above s5, bullet 1: s8 in RFC 3812 discusses the use of the Interface Table with MPLS. It should be made clear here: 1. Whether, if the MPLS-TP Tunnel is treated as an interface, there is any difference in the usage of the ifTable fields as compared with standard MPLS. In particular if a different interface type should be applicable. 2. Are there any issues if all or (more especially) a subset of the tunnels are not treated as interfaces Row pointer usage: s9 of RFC 3812 considers Row Pointer usage - are there any differences or additional considerations for these MIBs? s6: Sections 6.1 to 6.4 are not MIBs (as indicated by the title and prologue) but MIB objects in the MPLS-TE-EXT-STD-MIB MIB. Please reorganize s6 accordingly. Looking back at RFC3812, the structure of the document in sections 5 and 6 appears to be more helpful to the new reader with a summary of the four MIB modules in one section (expanded from ss6.5 - 6.7) followed by notes on the key MIB objects in each MIB as necessary. It would also be helpful to clarify where objects in this MIB are expected to parallel those in the basic (RFC 3812) and note that they are indexed equivalently (notably in the case of mplsTunnelTable and mplsTunnelExtTable). Nits/editorial comments: General: Consistent use of bi-directional or bidirectional: Please choose one and use it throughout. General: The qualifier "sparse" is used incorrectly in several places (e.g., sparsely extended). Presumably the intention is that the extensions are "slight" or "limited" . In most cases the term can be deleted: The degree of extension will ultimately be in the eyes of the implementer! (s5 - 2 cases, s6.4, s7 - 2 cases, s8, s9.1.6, s9.2.9, s9.3.6, s12 - 3 cases) General: The figures need number and captions. The numbers should be used to refer to the figures. s4, para 1: s/unidirectional tunnel/unidirectional tunnels/ s4, para 1, last sentence: s/re-use/re-use and extend/ s4, para 2: OLD: retained in the same document, instead of a separate document. NEW: all defined in this document, rather than split over several documents. s5, para 1: s/This document identifies/The MIBs in this document satisfy/ s5, para 2: s/The MIB module supports/The MIB modules, taken together, support/ s5, para 2: s/static and signaled/statically configured and dynamically signaled/ s5, bullet 4: s/sparsely extended/extended/ s9.1.6, s9.2.9, s9.3.6: s/a sparse augmentation/a limited augmentation/ s5, bullet 5: It would be helpful to explain how node identification differs from standard MPLS to understand why this mapping is needed. There appears to be text in s6.1 that might help but it is too late to make it easy to understand this section. ss10-13: It is conventional to give the RFCs used as references in the docuement s/RFC 3812/[RFC3812]/ etc. s14: This is a near duplicate of the security considerations in RFC 3812. It might be easier to reference that section and add a note that extra tables may provide further sensitive information. A brief discussion of whether the non-IP case makes any difference would be useful. s16: At the very least RFC 3811, RFC 3812 and RFC 3813 are normative. RFC 6923 probably is. RFC 6370 and RFC 4802 may also be.