Hi Peter, On 8/19/15, 3:27 PM, "Peter Psenak" <[email protected]> wrote:
>Hi Pushpasis, > >On 8/19/15 10:43 , Pushpasis Sarkar wrote: >> Hi Peter, >> >> On 8/19/15, 1:22 PM, "Peter Psenak" <[email protected]> wrote: >> >>> Stephane, >>> >>> there are two things involved here - configuration and advertisement. >>> >>> If you look at the SR drafts for both IGPs, both MTID and algorithm is >>> advertised with Prefix SID, not with SRGB. >> [Pushpasis] Again IMO, SRGBs published per topology and hence ISIS/OSPF >>SR >> extensions should be modified to add an optional MTID field as well. > >please bear in mind that there are implementation out there in the field >with the existing encoding. [Pushpasis] That’s why I said that MTID in SR-Capability should be optional. The SRGB for the default topology can be encoded without a MTID (no impact to current implementation). The SRGB for other topologies can be encoded with a MTID field. >If you move the MTID/algorithm fileds from >Prefix SID to SRGB, what is the MTID/algorithm fields in prefix SID used >for? [Pushpasis] The MTID in prefix TLV is for having the index associated with the prefix. If one uses the same index with differenet MTIDs(different topologies) the label allocated for the same prefix for the two different topologies shall be different. If the forwarding path for the prefix for one topology needs to be different than the other, having the same label for the same prefix for the two different topology is not an option. Hence we need a different SRGB for each topology. That’s why we need a MTID in the SR-Capability. >Having the MTID/algorithm fileds in both Perfix SID and SRGB would >be redundant and confusing. > >>> >>> That does not mean you have to manually configure prefix SID for each >>> MTID or algorithm - there are ways how this can be achieved in an >>> automated way while advertising a single topology/algorithm agnostic >>>SRGB. >> [Pushpasis] I am assuming by 'automated way’ you still mean separate >> indexes per topology for the same prefix. Right? > >advertisement wise yes, config wise no. [Pushpasis] I did not understand how advertisement can be different from configuration. In my understanding advertisements are derived from configurations. Thanks -Pushpasis > >thanks, >Peter >> >> Thanks >> -Pushpasis >>> >>> thanks, >>> Peter >>> >>> >>> On 8/19/15 09:36 , [email protected] wrote: >>>> Hi, >>>> >>>> We come back to the same discussion for MT as for per algorithm SRGB. >>>> Do we need for operational reason the same index value to be >>>>configured >>>> for different algorithm or topologies ? >>>> IMO, it is useful operationally otherwise adding a topology or >>>> algorithm would be painful ... Adding a new index value is like >>>> assigning a new prefix but here we want to use the same prefix. >>>> >>>> Stephane >>>> >>>> -----Original Message----- >>>> From: spring [mailto:[email protected]] On Behalf Of Pushpasis >>>> Sarkar >>>> Sent: Wednesday, August 19, 2015 09:06 >>>> To: Peter Psenak; Eric Rosen; SPRING WG >>>> Subject: Re: [spring] SRGBs, indexes, and topologies within a domain >>>> >>>> Hi Peter, >>>> >>>> On 8/19/15, 12:01 PM, "Peter Psenak" <[email protected]> wrote: >>>> >>>>> SR protocol extensions clearly do - they advertise MTID with the >>>>>prefix >>>>> SID, not with SRGB. >>>>> >>>> [Pushpasis] Do you mean that a separate index per topology is >>>>mandatory? >>>> That won¹t be a good idea in my opinion. Operators SHOULD have >>>> flexibility to choose a separate or same index for the same prefix >>>>under >>>> different topology. Not sure how other members (especially the >>>> operators) think about the same. Request SR authors to re-consider >>>>this. >>>> >>>> Thanks >>>> -Pushpasis >>>> >>>>> >>>> >>>> _______________________________________________ >>>> spring mailing list >>>> [email protected] >>>> https://www.ietf.org/mailman/listinfo/spring >>>> >>>> >>>> >>>>_______________________________________________________________________ >>>>__ >>>> ________________________________________________ >>>> >>>> Ce message et ses pieces jointes peuvent contenir des informations >>>> confidentielles ou privilegiees et ne doivent donc >>>> pas etre diffuses, exploites ou copies sans autorisation. Si vous avez >>>> recu ce message par erreur, veuillez le signaler >>>> a l'expediteur et le detruire ainsi que les pieces jointes. Les >>>> messages electroniques etant susceptibles d'alteration, >>>> Orange decline toute responsabilite si ce message a ete altere, >>>>deforme >>>> ou falsifie. 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