Re: Opinion on WG drafts for Multi-region/layer networks

[Dimitri.Papadimitriou@alcatel.be]

richard

> I understand what a region is
but see no definition of a multi-region 
> network anywhere.

see page 3. 

> For example, when is it the case that you don't
have a multi-layer 
> network? 

see section 3, in summary, it says
multiple regions always cover multiple layers but not the other way around

Richard Rabbat <richard@us.fujitsu.com> Sent by: owner-ccamp@ops.ietf.org 23/12/2005 22:20

To:        "Brungard, Deborah A, ALABS" <dbrungard@att.com>         cc:        Huub van Helvoort <hhelvoort@chello.nl>, LE ROUX Jean-Louis RD-CORE-LAN <jeanlouis.leroux@francetelecom.com>, adrian@olddog.co.uk, ccamp@ops.ietf.org         Subject:        Re: Opinion on WG drafts for Multi-region/layer networks

hi Deborah,
thanks for your comments.
sorry for being so slow today; must be the wine or is it the martini? :-)
Your description is different from that of JL as he is saying that MRN
is a special case of MLN but you're saying that they refer to different
planes.
I understand what a region is but see no definition of a multi-region 
network anywhere.
the lexico draft is clear in describing layers and regions but the 
MLN/MRN concepts don't seem to be defined.
For example, when is it the case that you don't have a multi-layer 
network? A network is by definition multi-layer since it follows some 
layering (OSI or otherwise). Is there a network that doesn't have a 
physical layer, mac layer and above?

thanks, and happy holidays!
Richard.

Brungard, Deborah A, ALABS wrote:

>Hi all,
>
>As JL notes, MLN is referring to data plane and MRN to (GMPLS) control
>plane. A MLN may support one ISC or multiple ISCs i.e. GMPLS regions
(a
>GMPLS region is defined in RFC 3495/4206,,).  In the updated
>requirements draft for Nov's meeting, we added text to clarify MRN
and
>MLN, refer to section 1 and 3.1:
>"A data plane layer is associated with a region in the control
plane
>(e.g. VC4 associated to TDM, IP associated to PSC). However, more than
>one data plane layer can be associated to the same region (e.g. both
VC4
>and VC12 are associated to TDM)."
>
>Richard, in the earlier versions of this draft, we thought also we
>should only use GMPLS constructs, and we had based the discussion on
>region. Though then many were confused how (control) region related
to
>(data) multi-layer networks. We included in this latest version both
>terms to help distinguish between the data plane and control plane.
>Similar to the lexio draft. Take a look at section 1 and 3.1, and if
you
>have suggestions, please send.
>
>(an eggnog/whisky/wine/martini should also help when reading - here
>(EST) it is just about that time - 'till next year - Good Holidays
>everyone)
>Deborah
>
>-----Original Message-----
>From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On
>Behalf Of Huub van Helvoort
>Sent: Friday, December 23, 2005 9:30 AM
>To: LE ROUX Jean-Louis RD-CORE-LAN
>Cc: Richard Rabbat; adrian@olddog.co.uk; ccamp@ops.ietf.org
>Subject: Re: Opinion on WG drafts for Multi-region/layer networks
>
>Hello JL,
>
>You explained:
>
>  
>
>>>two questions: 1. since MLN is a special case of MRN, can we
>>>collapse this whole topic to MRN? is there a compelling reason
for
>>>keeping these 2 notation?
>>>      
>>>
>>Actually a MLN is not a special case of MRN. Rather a MRN is a
>>special case of MLN. A network comprised of VC4 and VC4-64c capable
>>node is a MLN but not a MRN. "Layer" refers to a data
plane switching
>>layer (e.g. VC4, VC4-64c...). While "region" refers to
a switching
>>capablity (PSC, TDM...). The term MLN is used to discuss mechanisms
>>that apply equally to layers and regions (VNT...) while the term
MRN
>>is used to discuss multi-regions specific mechanisms (e.g. Adaptation
>>capability).
>>    
>>
>
>I am still confused by the definition of MRN.
>Suppose I have a TDM MRN, I can distinguish in this TDM MRN e.g.
>VC-12 layer switching, VC-4 layer switching, MS-n layer switching,
>so according to the above all MLN.
>Why is an MRN then a special case of MLN.
>
>With the next generation nodes: Multi Service Platforms within
>the same node there can also be ethernet switching on top of
>the above mentioned TDM MRN and optical switching (DWDM) below
>this TDM MRN....
>
>IMO the definition of MRN will be very difficult (impossible).
>
>I would propose to use only the MLN definition, with this layering
>and partitioning a network can be described completely.
>
>Cheers, Huub.
>
>  
>