Acee - Please see inline.
>-----Original Message----- >From: Acee Lindem <[email protected]> >Sent: Tuesday, July 14, 2026 1:15 PM >To: Les Ginsberg (ginsberg) <[email protected]> >Cc: lsr <[email protected]>; draft-admnr-lsr-igp-measurement- >[email protected] >Subject: Re: Questions on draft-admnr-lsr-igp-measurement-group-02 > >Hi Les, > >> On Jul 14, 2026, at 3:41 PM, Les Ginsberg (ginsberg) <[email protected]> >wrote: >> >> The latest version of the draft defines a modified form of the sub-TLV: >> 0 1 2 3 >> 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 >> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> | Type | Length | Group ID | AMP Protocol | >> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> | | >> | IPv4 or IPv6 Host Address (4 or 16 octets) | >> | | >> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ >> Several questions: >> 1) Given the Router Capability TLV carries V4 Router ID/V6 Router ID – why >> is >an application specific address necessary – and how would it be chosen? >> (I have asked this before but did not receive a substantive answer) > >Specification of the IP endpoint allows sessions with multiple endpoints on the >router. >We can discuss this requirement but using a different EP could be used to >measure a different path. > [LES:] You will need more than a different node address in order to measure a specific path. If that is what you are after I think you need more specification of how endpoint addresses are chosen. Until you do, I am seeing it as redundant with the already advertised router id that is carried in every Router Capability TLV. > >> 2) You are now requiring an address per “group ID”. Why? And how would a >group specific address be chosen? > >The Group ID allows AMP sessions amongst different disjoint groups of routers. >If this isn't a requirement, all routers in the domain can share the same Group >ID. [LES:] Understood. I am just saying the group ID is underspecified. More on that below. > > > >> 3) Section 4 states: >> “Given that an IP endpoint may be used for multiple measurement groups >> and AMP protocols, a router should only establish a single session of >> a given protocol type between the same two pairs of IP endpoints >> (independent of how many groups the endpoint participates in). “ >> This would argue that the encoding of the sub-TLV should be a list of Group >ID/AMP Protocol pairs so that unnecessary duplication is avoided. > >That encoding would be an option. However, this simply says that we don't >want to establish multiple AMP sessions for the same protocol between the >same two endpoints. >If you have two groups (1 and 2), it is entirely possible that two routers (A >and >B) would participate in both groups, where the other routers in groups 1 and 2 >are different. We wouldn't want multiple sessions between routers A and B. > [LES:] Understood. I am just asking that you be efficient in your encoding - something IS-IS has always been attentive to. >> 4) There is no discussion of what a group ID is nor how consistency in >configuration between nodes is achieved. > >Is this a trick question? How is configuration consistency ever achieved if not >incumbent on those doing the configuration? > [LES:] No - this isn’t a trick question. The group id simply isn’t specified. What numbers are valid? Are certain values reserved? Do they relate to anything in the associated protocol? It might be as simple as saying "the group id is an arbitrary number from 0-255" - but you haven't said anything. Les >Thanks, >Acee > > > >> Thanx. >> Les > _______________________________________________ Lsr mailing list -- [email protected] To unsubscribe send an email to [email protected]
