Hi Tony, Thanks for your question. Please see in line [Yali]. Please let me know your opinions.
Best, Yali -----Original Message----- From: Tony Li [mailto:[email protected]] Sent: Wednesday, November 18, 2020 1:41 AM To: wangyali <[email protected]> Cc: [email protected] Subject: Re: [Lsr] Discussion on draft-wang-lsr-hbh-process-00 > Q1: are you using this information to determine the routing to the network? > On one hand, such advertisement does not effect on the normal SPF computation > and may be useful for traffic engineering. For example, for IOAM service, if > the HbH Processing Action of Node/Link is assigned to a slow processing > plane, the Node or Link should be excluded for path computation. If the HbH > Processing Action of Node/Link is ignore all extension Options header, the > Node/Link can be used as the normal IPv6 transit node/link. If the HbH > Processing Action of Node/Link is skip to Next extension Options header (e.g. > Routing Header), the Node/Link can be considered as Endpoints in SRv6 > routing. On the other hand, such advertisement is useful for entities to > determine specific services encoded in HbH options header can be deployed in > a given path. > > Q2: can you use the link color to compute paths? > In the above, I answered, taking advantage of this advertisement, the exact > action taken by Node or Link to process HbH options header can be determined > (defined in Action Flag field), which can be useful for traffic engineering. > Hence, such advertisement is not only used to determine whether the HbH > options header supported by Node/Link or not. But the link color cannot > exactly indicate the exact action. This suggests that you’re missing one bit of information. Thus, could you use two link colors to differentiate between the two? [Yali] I am not clear what does the "... to differentiate between the two" mean? Please let me know if I'm missing something. [Yali] While please let me clarify what does the "Processing Action" include in this draft. The "Processing Action" indicates the various of configurable processing behavior for Hop-by-Hop Options header, which are specified in RFC8200. The "Processing Action" includes ignore the Hop-by-Hop Options header, skip to the next extension header, drop packets containing a Hop-by-Hop Options header, or assign packets to a slow processing path. Besides, the "Service Flag" is also defined in this draft used to indicate which service/function Options supported by Node/Link. [Yali] Hence, "two link colors" cannot differentiate the above vary combinations of "Processing Action Flag" and "Service Flag". Moreover, "Link Color" can only indicate whether or not include or exclude the Link for Traffic Engineering. But our use cases mentioned in Q1 is not so simple. Tony _______________________________________________ Lsr mailing list [email protected] https://www.ietf.org/mailman/listinfo/lsr
