Subject: RE: Identifiers (was Re: Minutes and action items from IETF 57)

From: [email-masked]
Date: Mon, 4 Aug 2003 15:44:41 +0100

Eric Rosen wrote 04 August 2003 15:01
> > Luca - why is 32 bits not enough?
> 
> > Vach - 32 bits is not enough for inter-galatic VPLS (really not
> >        sufficient for inter-region and inter-AS VPLS)
> 
> > Luca - lets do it in 1000 years then
> 
> I thought this was well understood, but I guess not.  
> 
> If a  single PW can  have its endpoints  in different SP 
> networks,  then the
> naming space  needs to be structured so  that the SPs can  
> each administer a
> piece of the  naming space without fear of naming  conflicts. 
>  I don't think
> it will be 1000 years before there is an inter-provider pw. 
> 
> There are also other reasons for  adding structure to the 
> name, as indicated
> in the various signaling and auto-discovery documents. 
> 
> > Luca - just introduce a TLV and call it "name"
> 
> The problem with this is that (a) it doesn't provide the 
> necessary structure
> and (b) will cause interoperability problems. 

NH=> I agree.  But there is a deeper issue here than 'naming' ....and its
also a much more generic/fundamantal issue than any specific VPN/service
instance.  Put simply the problem is that it is the LSPs themselves (not the
artifical PW client/server adaptation instances) that require access point
*addresses*.  Unfortunately, this clearly exposes the fact that MPLS must
become a layer network in its own right whose addressing is decoupled from
any specific client....including IP.  It can use the IP (v4 or v6) address
structure, but the actual address space belongs to the MPLS layer network
not the IP (or any other) layer network.

I and many colleagues have been aware of the need to face up to this for
several years now.  In fact, when I drafted the original version of Y.1711 I
pre-empted the need for MPLS layer addressing in the CV packet, based on v6
format (which can also take a v4 structure if required).

However, and as we all know only too well, some have a 'desire' to keep MPLS
too tightly bound to IP, and this is not doing it any favours
architecturally.....and in turn this is not doing me any favours as an
operator seeing/knowing problems like this exist when they really need
properly sorting out if MPLS is to achieve its potential.

regards, Neil