MPLS Label Switched Path (LSP) Pseudowire (PW) Status Refresh Reduction for Static PWs
draft-ietf-pals-status-reduction-05
Yes
(Deborah Brungard)
No Objection
(Alvaro Retana)
(Ben Campbell)
(Suresh Krishnan)
Note: This ballot was opened for revision 04 and is now closed.
Warren Kumari
No Objection
Comment
(2017-04-10 for -04)
Unknown
I agree with Benoit re: Jürgen's review. I was also quite confused by: " In order to get a locally unique session ID, the recommended choice is to perform a CRC-16 giving as input the following data |Y|Y|M|M|D|D|H|H|M|M|S|S|L|L|L| Where: YY: are the decimal two last digit of the current year MM: are the decimal two digit of the current month DD: are the decimal two digit of the current day HHMMSSLLL: are the decimal digits of the current time expressed in (hour, minutes, seconds, milliseconds) ... Any other method to generate a locally unique session ID is also acceptable." Is the pipe character intended to mean concatenation? Or is it just for formatting? If the former, why isn't this "YY|MM|DD|HHMMSSLLL" (or "YY|MM|DD|HH|MM|SS|LLL")? Is this just CRC-16 (170410124223001)? An example would help... Actually, this says that it is a "locally unique session ID" and that any other method is also acceptable, so why is any algorithm specified?
Deborah Brungard Former IESG member
Yes
Yes
(for -04)
Unknown
Alexey Melnikov Former IESG member
No Objection
No Objection
(2017-04-12 for -04)
Unknown
8.3. PW Status Refresh Reduction Notification Codes IANA needs to set up a registry of "PW status refresh reduction Notification Codes". These are 32-bit values. Type value 0 through 7 are defined in this document. Type values 8 through 65536, and 134,217,729 through 4,294,967,294 are to be assigned by IANA using the "Expert Review" policy defined in RFC5226. Type values 65536 through 134,217,728, 0 and 4,294,967,295 are to be allocated using the IETF review policy defined in [RFC5226]. For each value assigned IANA should also track whether the value constitutes an error as described in Section 5.1. When values are assigned by IETF Review, the setting of this column must be documented in the RFC that requests the allocation. For Expert Review and FCFS assignments, the setting of this column must be made clear by the requester at the time of assignment. FCFS policy is not used in this document, so it shouldn't be mentioned. Or possibly you meant "IETF Review" here?
Alia Atlas Former IESG member
(was Discuss)
No Objection
No Objection
(2017-06-29)
Unknown
Thanks for addressing my concerns.
Alissa Cooper Former IESG member
No Objection
No Objection
(2017-04-11 for -04)
Unknown
From Dan's Gen-ART review: Nits/editorial comments: 1. In section 8, first paragraph: s/rages/ranges/ 2. In sections 8.3, 8.4 the construct "IETF Review" is worded in three different ways (IETF review, IETF Review, "IETF Review") - better align
Alvaro Retana Former IESG member
No Objection
No Objection
(for -04)
Unknown
Ben Campbell Former IESG member
No Objection
No Objection
(for -04)
Unknown
Benoît Claise Former IESG member
No Objection
No Objection
(2017-04-10 for -04)
Unknown
As mentioned by Jürgen in his OPS-DIR review: Section 1.2 is not really about terminology but instead it basically expands acronyms. The section does not define any terms or does it make it clear where terms are defined. A reader who does not know T-PE will not be pointed to a document that defines 'Terminating Provider Edge Node of MS-PW'. I usally find terminology sections more useful if they say where definitions of terms get be found. Section 3: s/the the/the/ Section 4: What is the 'Version' field in the message format? Section 4: There is an 8-bit field marked U C Flags and I _assume_ the U and C bits are the 'first' two bits and the 'remaining bits are the flags managed by IANA. Perhaps make this clearer, e.g.: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Last Received Seq Number | Message Type |U|C| Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Or alternatively simply name the entire 8-bit flags field like you do in the text where you refer to Message Flags and then explain in the text under the 'Message Flags' that the first two bits have a fixed meaning. +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Last Received Seq Number | Message Type | Message Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ This option carries less information but then you use 'Message Flags' in several places and you also request an IANA registry for Message Flags where the U and C bit are allocated. Looking at the IANA text, it says 'bit position' 0 and 1. Not sure this is clear enough, you seem to number bits in the order 0, 1, 2, ... It turns out we have several slightly different labels further down in the document for this flags field throughout the document - this makes searching in the text difficult, please use a single consistent name for this message field. Section 8.2 says values 1 and 2 are defined in this document but then it seems value 3 is also allocated, no? Subsections of section 8 switches several times between decimal and hexadecimal numbers. Perhaps things get clearer if a single number system (e.g., hexadecimal) is used when talking about a specific registry. Numbers like 134,217,728 look somewhat confusing, 0x8000000 seems simpler.
Eric Rescorla Former IESG member
No Objection
No Objection
(2017-04-11 for -04)
Unknown
S 1. Periodic retransmission of non-zero status messages, and a simple acknowledge of PW status "acknowledgement", perhaps? S 2. I found the state machine here a bit hard to follow. Some sort of diagram might help. S 4. This is kind of an odd recommendation for how to generate the session ID. Why not just Hash(timer) rather than hash of an ASCII formatted date? S 5. The C Bit is used to signal the end of PW configuration transmission. If it is set, the sending PE has finished sending all it’s current configuration information. "its" Is last received sequence number a cumulative ack or the temporarally last received packet? S 5.2 Is Length the remaining length or the length of the entire TLV?
Kathleen Moriarty Former IESG member
No Objection
No Objection
(2017-04-11 for -04)
Unknown
I agree with Yaron's comment from the SecDir review. We shouldn't refer back to old security considerations sections, but rather revisit the considerations with current threats.
Mirja Kühlewind Former IESG member
No Objection
No Objection
(2017-04-12 for -04)
Unknown
(important) nit in section 8.5: s/PW Sytatus Refresh Reduction/PW Status Refresh Reduction/
Spencer Dawkins Former IESG member
No Objection
No Objection
(2017-04-09 for -04)
Unknown
In this text, -iii. If the new value is smaller then the original one, the PE will operate according to the original timer value for a period 3.5 times the original timer value, or until the first valid PW status refresh reduction message is received. Perhaps it would be helpful to explain the choice of 3.5, so that if this mechanism is deployed for a network where that number is the wrong number, people will know how to adjust it? There are several occurrences where s/then/than/ is needed, I think. I spotted at least 3. Other nits … S/octetc/octets/ S/RECOMENDED/RECOMMENDED/ S/vaules/values/ In section 7. Security Considerations The security considerations of [RFC6478] are adequate for the proposed mechanism since the operating environment is almost identical to the one where this protocol would be deployed. It should also be noted that since this protocol is designed to be deployed between two adjacent PEs connected by a physical link, it is not possible to misdirect or inject traffic without compromising the PW transport link itself. All these situations are covered in the security considerations of [RFC6478]. There's an appeal to physical adjacency as a defensive mechanism. If this protocol is deployed in a tunnel over UDP, would “physical adjacency” still be true?
Suresh Krishnan Former IESG member
No Objection
No Objection
(for -04)
Unknown