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

From: "Brungard, Deborah A, ALABS" <[email-masked]>
Date: Fri, 23 Dec 2005 14:05:53 -0600

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: [email-masked] [mailto:[email-masked]] 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; [email-masked]; [email-masked]
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.

-- 
================================================================
              http://members.chello.nl/hhelvoort/
================================================================
Always remember that you are unique...just like everyone else...

---

From: Richard Rabbat <[email-masked]>
Date: Fri, 23 Dec 2005 13:20:00 -0800

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.

---

From: Huub van Helvoort <[email-masked]>
Date: Fri, 23 Dec 2005 23:31:50 +0100

Helli Deborah,

Thanks for the clarification,
after reading draft-shiomoto-ccamp-gmpls-mrn-reqs
the definitions are more clear to me.
(even with my handicap ;-)

Happy Holidays to all of you.  Huub.

---

From: [email-masked]
Date: Sat, 24 Dec 2005 00:54:31 +0100

richard

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

see page 3. 

> network? 

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

Richard Rabbat <[email-masked]>
Sent by: [email-masked]
23/12/2005 22:20
 
        To:     "Brungard, Deborah A, ALABS" <[email-masked]>
        cc:     Huub van Helvoort <[email-masked]>, LE ROUX 
Jean-Louis RD-CORE-LAN <[email-masked]>, 
[email-masked], [email-masked]
        Subject:        Re: Opinion on WG drafts for Multi-region/layer 
networks

hi Deborah,