The MPLS WG Archive

[Alex Zinin <azinin@cisco.com>]

Hi Darren!

> Hi Alex,

>>>> - "server layer trails (in an OTN) = client layer links", and
>>>> networks operators *will* have to support multiple client
>>>> layers for a very long time...including some large BW servives
>>>> directly off the L1 fabric.
>>>> 
>>>> This is a really important point.  It is a fundamental
>>>> characteristic of a layered network architecture.
>>
>> [AZ] Got it. I didn't realize what layers you meant.

> This is the first time I have actually seen anyone on the MPLS or IPO lists
> publicly acknowledge the "client layer links = server layer trails" fact.

I think this was quite clear. If you establish an LSP across your
optical network, it will look like a link to your client.

> I assume then that you now also acknowledge the single control plane 'Peer'
> model as being impractical?

Wrong assumption.

> Okay, using a single 'best of breed' routing
> protocol

Wrong assumption (OSPF+ISIS).

>  and a single 'best of breed' signalling protocol

Wrong assumption (RSVP-TE + CR-LDP).

> across the IP and
> optical layers may be feasible (I stress may), but it follows from the above
> simple concept (as Neil Harrison stated before) that the addresing scheme
> used by the optical layer cannot be related to any particular clients (ie
> not from the same addressing space in terms of possible trail connectivity
> at layer network access points).

Wrong assumption.
I does not have to be related, but it can.

>   Sure this would not be the case if IP was
> the only client of the optical layer, but (*reality check*), operators WILL
> still be making most of their revenue from non-IP clients for a long time to
> come, and therefore an optical transport network WILL have to support
> multiple clients.

Do you mean there is a contradiction with the work currently being
done?

> Are we now seeing a realisation of this in the IETF?  I think it's obvious
> that what was defined as the 'Overlay' model in
> draft-awduche-mpls-te-optical-02.txt and
> draft-many-ip-optical-framework-01.txt must be developed first.

I would say we should develop the OTN control plane first.

Regards,
Alex.