The MPLS WG Archive

["Abarbanel, Benjamin" <Benjamin.Abarbanel@Marconi.com>]

Title: RE: MPLSOAM BOF revised minutes

I think MPLS was never officially dubbed a "layer" unto itself because it was shoehorned into the

the stack by designers after the existing TCP/IP protocols were defined. I have a rather uncomfertible

feeling calling it a new layer. What is it layer 2.5?  It intimately depends on layer 3 (IP for initial signalling) and 4(OSPF, ISIS, BGP, etc. for routing topology). To me a layer is one that exhibits alot of independent attributes. 

 

Ben

-----Original Message-----
From: David Allan [mailto:dallan@nortelnetworks.com]
Sent: Wednesday, December 19, 2001 5:34 PM
To: Loa Andersson; Don Fedyk
Cc: Yakov Rekhter; Shahram Davari; 'mpls@UU.net'
Subject: RE: MPLSOAM BOF revised minutes

 Folks:
 
 Don't care what you term it, an MPLS "level" performs
 forwarding, is managagable, has unique modes of failure, may
 be uniquely manipulated by a control plane, collects
 performance statistics, offers queuing and scheduling....
 
 and it can RECURSE, in some ways a similar attribute to
 .....IP/PPP/L2TP/IP.... or .....IP/GRE/IP...... or
 OC3/OC12/OC48/OC192/OC768
 
 in some folks book it can be a bunch of layers.....in other
 folks book it is a helper of arbitrary complexity, all
 depends on which control plane fiddles the cross connect and
 whether the application is a peer or overlay model.
 
 regardless of what semantic term you use or how you justify
 your classiciation on the basis of arcane networking models,
 each level is a unique forwarding plane with unique
 attributes, everything else derives from that. Merely
 claiming that the only application of a unique forwarding
 layer is a helper is akin to suggesting export controls on
 encryption. The cat is out of the bag by the mere fact of its
 existence.
 
 cheers
 Dave

P.S. apologies if anyone got this twice.
> ----------------------------------------
>
> Don,
>
> I nevr claimed that MPLS is layer, I've always claimed that MPLS
> is something entirely different. I use MPLS as a toolbox to support
> my IP network.
>
> /Loa
>
> > Don Fedyk wrote:
> >
> > Loa
> >
> > I don't know what you are getting at. MPLS is recognizable
> > in the forwarding plane. Yakov said this is not a requirement.
> > I pointed out that while this is true, in practice, for whatever
> > reason we end up putting a recognizable layer in the forwarding
> > plane. I just called it like I see it. If you want to build a new
> > OSI model to describe this then that is your prerogative. I don't
> > see the need.
> >
> > Don
> >
> > > -----Original Message-----
> > > From: Loa Andersson [mailto:loa.andersson@utfors.se]
> > > Sent: Wednesday, December 19, 2001 11:34 AM
> > > To: Fedyk, Don [BL60:1A00:EXCH]
> > > Cc: Yakov Rekhter; Shahram Davari; 'mpls@UU.net'
> > > Subject: Re: MPLSOAM BOF revised minutes
> > >
> > >
> > > Don,
> > >
> > > what other layers are there in the model that MPLS is a layer
> > > within?
> > >
> > > /Loa
> > >
> > > > Don Fedyk wrote:
> > > >
> > > > Loa
> > > >
> > > > My comment was in practice we treat it a layer. We should
> > > > recognize that. Others have commented on the fact the OSI model
> > > > does not capture all.
> > > >
> > > > Don
> > > >
> > > > >
> > > > > > Don Fedyk wrote:
> > > > > >
> > > > > > Yakov
> > > > > >
> > > > > > I think MPLS is a layer in its own right.
> > > > > >
> > > > >
> > > > > Do you say that MPLS is a layer according to the OSI model?
> > > > >
> > > > > /Loa
> > > > >
> > > > > --
> > > > > Loa Andersson
> > > > > Chief Architect,
> > > > > Utfors Research, Architecture and Future Lab (URAX)
> > > > > Utfors AB
> > > > > Råsundavägen 12
> > > > > Box 525, 169 29 Solna
> > > > > Office          +46 8 5270 2000
> > > > > Office direct   +46 8 5270 5038
> > > > > Mobile          +46 70 848 5038
> > > > > Email           loa.andersson@utfors.se
> > > > > WWW             www.utfors.se
> > > > >
> > >
> > > --
> > > Loa Andersson
> > > Chief Architect,
> > > Utfors Research, Architecture and Future Lab (URAX)
> > > Utfors AB
> > > Råsundavägen 12
> > > Box 525, 169 29 Solna
> > > Office          +46 8 5270 2000
> > > Office direct   +46 8 5270 5038
> > > Mobile          +46 70 848 5038
> > > Email           loa.andersson@utfors.se
> > > WWW             www.utfors.se
> > >
>
> --
> Loa Andersson
> Chief Architect,
> Utfors Research, Architecture and Future Lab (URAX)
> Utfors AB
> Råsundavägen 12
> Box 525, 169 29 Solna
> Office          +46 8 5270 2000
> Office direct   +46 8 5270 5038
> Mobile          +46 70 848 5038
> Email           loa.andersson@utfors.se
> WWW             www.utfors.se
>
> ---------------------------------
> Sr. Advisor, Portfolio Integration and Architecture
> dallan@nortelnetworks.com
>
>