Re: cleaned up question sheet

[Rob Coltun <rcoltun@redback.com>]

thanks - wasn't at the last meeting and didn't see any notes. I'll start digging in
(a bit difficult from Europe).

---rob

Jim Boyle wrote:

> I think the plan is for any/all of us to answer these by today-ish, using
> whatever resources we have at our command, and then we were going to
> discuss and try to extract the essential requirements from the mix.  At
> least that was the gameplan.  today-ish in ietf time might take a week or
> so though.  Definitely the plan was to kick up the heat this week on this
> mailing list, and I suppose 3 messages is hotter than 1.
>
> What are your thoughts on how we proceed?
>
> Jim
>
> On Tue, 3 Jul 2001, Rob Coltun wrote:
>
> > Thanks Jim - is there a game plan from this point moving forward?
> >
> > thanks,
> > ---rob
> >
> > Jim Boyle wrote:
> >
> > > took a pass at cleaning up the question sheet, no new content.
> > >
> > > ------* snip here *--------
> > > A. Definitions
> > >
> > > 1. In determining the specific requirements, the design team should
> > >    precisely define  the concepts "survivability", "restoration",
> > >    "protection", "protection switching", "recovery", "re-routing"
> > >    etc. and their relations. This would enable the requirements doc to
> > >    describe precisely which of these will be addressed.
> > >
> > >    In the following, the term "restoration" is used to indicate the broad
> > >    set of policies and mechanisms used to ensure survivability.
> > >
> > > B. Network types and protection modes
> > >
> > > 1. What is the scope of the requirements with regard to the types
> > >     of networks covered? Specifically, are the following in scope:
> > >
> > >     -  Restoration of connections in mesh optical networks
> > >        (opaque or transparent)
> > >     -  Restoration of connections in hybrid mesh-ring networks
> > >     -  Restoration of LSPs in MPLS networks (composed of LSRs overlaid on a
> > >        transport network, e.g., optical)
> > >     -  Any other types of networks?
> > >     -  Is commonality of approach, or optimization of approach more important?
> > >
> > > 2.  What are the requirements with regard to
> > >      the protection modes to be supported in each network type covered?
> > >      (Examples of protection modes include 1+1, M:N, shared mesh,
> > >      UPSR, BLSR, newly defined modes such as P-cycles, etc.)
> > >
> > > 3.  What are the requirements on local span (i.e., link by link)
> > >      protection and end-to-end protection, and the interaction between them?
> > >      E.g.: what should be the granularity of connections for
> > >      each type (single connection, bundle of connections, etc).
> > >
> > > C. Hierarchy
> > >
> > > 1. Vertical (between two network layers):
> > >     What are the requirements for the interaction between restoration
> > >     procedures across two network layers, when these features are
> > >     offered in both layers?
> > >     (Example, MPLS network realized over pt-to-pt
> > >     optical connections.) Under such a case,
> > >
> > >     (a) Are there any criteria to choose which layer should provide
> > >           protection?
> > >
> > >     (b) If both layers provide survivability features, what are the
> > >           requirements to coordinate these mechanisms?
> > >
> > >     (c) How is lack of current functionality of cross-layer
> > >           cooridnation currently hampering operations?
> > >
> > >     (d) Would the benefits be worth additional complexity associated
> > >           with routing isolation (e.g. VPN, areas), security, address
> > >           isolation and policy / authentication processes?
> > >
> > > 2. Horizontal (between two areas or administrative subdivisions within
> > >     the same network layer):
> > >
> > >     (a) What are the criteria that trigger the creation of protocol or
> > >           administrative boundaries pertaining to restoration? (e.g.,
> > >           scalability?  multi-vendor interoperability? what are the
> > >           practical issues?)  multi-provider? Should multi-vendor
> > >           necessitate hierarchical seperation?
> > >
> > >     When such boundaries are defined:
> > >
> > >     (b) What are the requirements on how protection/restoration is
> > >           performed end-to-end across such boundaries?
> > >
> > >     (c) If different restoration mechanisms are implemented on two
> > >           sides of a boundary, what are the requirements on their
> > >           interaction?
> > >
> > >    What is the primary driver of horizontal hierarchy? (select one)
> > >     - functionality (e.g. metro -v- backbone)
> > >     - routing scalability
> > >     - signalling scalability
> > >     - current network architecture, trying to layer on TE ontop of
> > >       already hiearchical network architecture
> > >     - routing and signalling
> > >
> > >    For signalling scalability, is it
> > >     - managability
> > >     - processing/state of network
> > >     - edge-to-edge N^2 type issue
> > >
> > >     For routing scalability, is it
> > >     - processing/state of network
> > >     - are you flat and want to go hierarchical
> > >     - or already hierarchical?
> > >     - data or TDM application?
> > >
> > > D. Policy
> > >
> > > 1. What are the requirements for policy support during
> > > protection/restoration,
> > >     e.g., restoration priority, preemption, etc.
> > >
> > > E. Signaling Mechanisms
> > >
> > > 1. What are the requirements on the signaling transport mechanism
> > >    (e.g., in-band over sonet/sdh overhead bytes, out-of-band over
> > >    an IP network, etc.) used to communicate restoration protocol
> > >    messages between network elements. What are the bandwidth and
> > >    other requirements on the signaling channels?
> > >
> > > 2. What are the requirements on fault detection/localization mechanisms
> > >    (which is the prelude to performing restoration procedures)
> > >    in the case of opaque and transparent optical networks?
> > >    What are the requirements in the case of MPLS restoration?
> > >
> > > 3. What are the requirements on signaling protocols to be used in
> > >    restoration procedures (e.g., high priority processing, security, etc).
> > >
> > > 4. Are there any requirements on the operation of restoration protocols?
> > >
> > > E. Quantitative
> > >
> > > 1. What are the quantitative requirements (e.g., latency) for completing
> > >    restoration under different protection modes (for both local and
> > >    end-to-end protection)?
> > >
> > > F. Management
> > >
> > > 1. What information should be measured/maintained by the control plane at
> > >     each network element pertaining to restoration events?
> > >
> > > 2. What are the requirements for the correlation between control plane
> > >     and data plane failures from the restoration point of view?
> >