Re: Stepping back from the ASON Routing Discussion

[Dimitri.Papadimitriou@alcatel.be]

adrian, so let me try to recap here, what are the combination
using the terminology you were introducing that are w/i scope

1) R(i) 1:1 L(i) with every L(i) 1:1 P(i)
2) R(i) 1:n L(j) with every L(j) 1:1 P(j)
3) R(i) 1:1 L(i) with every L(i) 1:m P(j)
4) R(i) 1:1 L(i) with some  L(i) 1:0 P(j) and some L(i) 1:1 P(i)
5) R(i) 1:n L(j) with some  L(j) 1:0 P(k) and some L(j) 1:1 P(j)

if this is the case, are we missing something that needs to be
further covered ?

also there is no discussion here about DP<->CP realization and
or physical co-location issue(s), this is completely orthogonal
to the present discussion (some responses on the list show this
is still not clearly integrated)

Adrian Farrel wrote:
> Don,
>
> Just picking out one snippet...
>
>
> > > > Do we, or do we not need to support a physically separated
> > > > architecture with a 1-n relationship between control plane
> > > > and transport plane entities?
> > >
> > > I would say yes. The requirement I see here is devices not capable of
> > > participating fully in GMPLS routing.
>
>
> I had to read this several times before I got it. Sorry.
>
> You mean that...
> "It is a requirement of ASON routing to support networks that contain devices that do not
> contain the capabilities to participate fully (or at all) in the routing protocols run
> within the network."
>
> That sounds a reasonable requirement.
>
> There are two developments of this requirement.
>
> The first is where the routing responsiblity for the device is taken on "by proxy" by a
> control plane entity such as one that Lyndon, Jonathan and I have been drawing. In this
> case, although the device is not participating in the routing protocols within the
> network, it is fully represented and there are no issues (although we must ensure that
> this function is covered by the requirements).
>
> In the second case, ther are islands within the network which are simply not represented
> to the routing protocol. This gives me a greater problem. Clearly you cannot route through
> a part of the network unless it appears to be connected in the TEDB. In this case, I
> suggest that what is needed is to represent those (legacy?) devices/subnetworks as
> Forwarding Adjacencies or virtual TE links. This requires some advertisement by a control
> plane entity on behalf of the devices/subnetworks, but does not expose the details of the
> connectivity of the devices that do not support routing.
>
> Some of you may (from time to time) hear me burble on about the fact that soft permanent
> LSPs should not simply cover the case where the permanent part is at the edge of the
> network. When I ramble in this way, I am talking about the second case, above.
>
> Cheers,
> Adrian

--
Papadimitriou Dimitri
E-mail : dimitri.papadimitriou@alcatel.be
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