The MPLS WG Archive

[Hummel Heinrich <Heinrich.Hummel@icn.siemens.de>]

Shahram,
A label that pilots the packet (which is e.g. a Label_Request message) to the next hop router rather than by longest prefix match.

To make it clear: 

Such kind of label hasn't been specified by any MPLS protocol yet ! 
You are absolutely right: So far, Control-plane messages are not sent as labeled packets, rather they are sent as IP packets.


Yours,
Heinrich 
> -----Urspr> üngliche Nachricht-----
> Von:	Shahram Davari [SMTP:Shahram_Davari@pmc-sierra.com]
> Gesendet am:	Freitag, 1. Dezember 2000 14:15
> An:	'Hummel Heinrich'; 'George Swallow'; Dawkins, Spencer
> Cc:	mpls@UU.NET
> Betreff:	RE: New MPLS charter 
> 
> Hummel,
> 
> What is a control-plane label? Control-plane messages are not sent as labeled packets, rather they are sent as IP packets.
> 
> Yours,
> -Shahram
> 
> > -----Original Message-----
> > From: Hummel Heinrich [mailto:Heinrich.Hummel@icn.siemens.de]
> > Sent: Friday, December 01, 2000 4:52 AM
> > To: 'George Swallow'; Dawkins, Spencer
> > Cc: mpls@UU.NET
> > Subject: AW: New MPLS charter 
> > 
> > 
> > Georg,
> >   
> > you wrote"...we can define new ways of carrying labels where 
> > new kinds of link layers may emerge out of the Optical work".
> > Let me think in this direction:
> > Let me call all so far defined LSPs "User Plane LSPs" because 
> > they  transmit user data (in such a way that no transit-LSR will
> > evaluate the IP Header of the user data packets).
> > We may define as well "Control Plane LSPs": They should 
> > transmit only messages for establishing/terminating User Plane LSPs.
> > Hereby the "Control Plane" labels should only be used to 
> > determine the next hop( = replacement of the longest prefix 
> > match mechanism).
> > Each transit-LSR should evaluate the IP Header and even the entire
> > "Control Plane" packet =MPLS-message like RSVP-PATH or a 
> > CRLDP-LABEL_REQUEST,... 
> > Remains the question how and when to install the NHLFEs of 
> > the "Control Plane" labels: Well, BGP4, PIM, LDP-unsolicited
> > downstream may be used to install them.
> > 
> > The benefit: The establishing of User Plane LSPs by means of 
> > RSVP resp.  LDP-downstream-on-demand, can be done 
> > almost as fast as transmitting user data by the User Plane LSP.
> > 
> > Another goal:
> > Studying and specifying the case where a Control Plane LSP 
> > and any of its associated User Plane LSPs only share
> > the common endpoints but not the route between these endpoints.
> > 
> > 
> > What do you think ?
> > 
> > Heinrich Hummel
> > Siemens AG
> > heinrich.hummel@icn.siemens.de
> >  
> > 
> > 	
> > --------------------------------------------------------------------- 
> > > Spencer -
> > > 
> > > The way I read that (and I would like to be wrong on this, but doubt
> > > that I am) is we can define new ways of carrying labels where new
> > > kinds of link layers may emerge out of the Optical work.  
> > Also I don't
> > > really anticipate any need in that area, since we already have an
> > > encapsulation over PPP and PPP is likely to be defined over 
> > any thing
> > > that emerges out of the optical work.
> > > 
> > > ...George
> > > 
> > > ==================================================================
> > > George Swallow       Cisco Systems                   (978) 244-8143
> > >                      250 Apollo Drive
> > >                      Chelmsford, Ma 01824
> >