Gert, You are right. When the user configures an abstract link specifying the underlay topology path, the user essentially provides a set of inclusion constraints for the trail supporting the link. Although it is not reflected yet in the TE-TOPO model, it should be possible to specify whether it is acceptable or not to deviate from said constraints on the trail setup and/or during its lifetime (e.g. in case of restoration). One server side implementation you and I are aware of has this capability already.
Kind regards, Igor -----Original Message----- From: Gert Grammel [mailto:[email protected]] Sent: Friday, October 23, 2015 4:16 PM To: Igor Bryskin <[email protected]> Cc: Alexander Clemm (alex) <[email protected]>; Martin Bjorklund <[email protected]>; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected] Subject: Re: [i2rs] WG LC for Topology (10/1 to 10/14) Hi Igor, It would be advisable to let the client decide whether a different underlay shall invalidate the intended config. Best Gert Sent from my Apple ][ > On 23 Oct 2015, at 15:00, Igor Bryskin <[email protected]> wrote: > > Hi Martin, > > It is possible that a user configures a link of a customized (user defined) > topology providing also the path defined in underlay server defined topology. > Said underlay path needs to be considered as intended configuration. Actual > underlay path will be state data in this case ( personally I also do not see > a difference between state and server provided data), which may or may not > match the intended underlay path. The actual underlay path may also change > over time due, for example, network failure restoration procedures affecting > the underlay topology. > The link of the user defined topology is not invalidated in this case. User > just has to deal with the fact that the intended configuration may not > necessarily match the actual configuration and state data. > > Cheers, > Igor > > -----Original Message----- > From: i2rs [mailto:[email protected]] On Behalf Of Alexander Clemm (alex) > Sent: Thursday, October 22, 2015 8:12 PM > To: Martin Bjorklund <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; [email protected] > Subject: Re: [i2rs] WG LC for Topology (10/1 to 10/14) > > Hi Martin, > > Agree, we need to add text for this. Good catch. > > The reality is that the integrity of the links between overlay and underlay > will be broken. The fact that those links will be invalidated is something > that ultimately needs to be indicated. > > Since the interface analogy was brought up, this problem is actually faced by > layered interfaces that are user controlled as as well. What is the solution > that is applied there? (I guess it is basically left up to the application, > correct?) > > --- Alex > > -----Original Message----- > From: Martin Bjorklund [mailto:[email protected]] > Sent: Monday, October 19, 2015 11:04 PM > > ..... > > > What happens in your model if a user-defined network has a reference to a > server-provided network, and the sever decides to remove its network? I see > no special text in your document about this case. > > > > > _______________________________________________ > i2rs mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/i2rs > > _______________________________________________ > i2rs mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/i2rs _______________________________________________ i2rs mailing list [email protected] https://www.ietf.org/mailman/listinfo/i2rs
