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-pwe3-redundancy-06 Reviewer: Martin Thomson Review Date: 2012-03-15 IETF LC End Date: 2012-03-21 IESG Telechat date: (if known) Summary: The draft has some minor issues. Major issues: none Minor issues: 3.2.2 states: "The mechanisms for achieving this selection are outside the scope of this document." The example then describes the _conditions_ under which the selection is made. So the statement doesn't quite make sense. It's reasonable to presume that a standard doesn't prescribe the internal behaviour of a PE where interoperability is no concern. Even though this is just an example, it makes a very specific presumption about the behaviour of the PE in reaction to an event. I can't imagine any other reaction in this case, so I'm left wondering: what exactly is out of scope for this? Communication of the event between PE1 and PE2? Section 4.1: "Non-revertive behavior MUST be supported, while revertive behavior is OPTIONAL." The reason for this requirement is non-obvious (at least to me). Some justification for it seems appropriate. Section 4.1: "Protection switchover can be triggered by the operator [...]" Again, justification would be nice. This actually smells more like a product specification that requirement for interoperability. If the requirement is, as I suspect, that switchovers triggered by manual intervention can be marked as such in the protocol _so that they can be treated with lower priority_, then that is definitely understandable. Section 4.2: "[...] MUST support the configuration of revertive or non-revertive protection switching modes." If revertive switching is optional, then this requirement makes not sense for (T-)PEs that don't implement it. Nits: The figures are somewhat difficult to read overall. It's unclear what significance is attached to the dots in many of the diagrams, since they aren't always consistent (see Figure 3). Figure 5 is especially difficult to read. Another instance is the choice of '.' or '|' in Figure 4, which could have some significance, but probably doesn't because the usage is quite inconsistent. Having labels for lines/tunnels impinge on boxes is difficult to interpret. Reducing the noise in the diagrams would help. The text is adequate to make up the shortfall. (Figure 7 is perfectly clear.) Labeling of PEs in 3.2.2 makes it hard to follow because PE2 is attached to CE2. I'd suggest renames such that you have {CE1, PE1a, PE1b} and likewise. The first requirement in 4.1 is missing a couple of spaces (after the comma, in "besupported"). 4.2 has an empty bullet. Not expanded on first use: PSN, LDP