The MPLS WG Archive

["Chris LaVallee" <clavallee@zumanetworks.com>]

> -POS the ether type will be 0x8847 or 0x8848 (as oppsed to 0x0800 for IP)

This might be off topic, but...

How do you get an ethertype over POS ? 
I'm guessing it's Cisco-HDLC (which I know nothing about)

PPP over POS has 2 other possibilities to carry MPLS
- Add a new CP (control proto) for MPLS
- Have BCP (PPP Bridging) carry MPLS

Anyone have a preference / opinion on what people should use ?

Chris




> -----Original Message-----
> From: owner-mpls@UU.NET [mailto:owner-mpls@UU.NET]On Behalf Of James R.
> Leu
> Sent: Friday, June 02, 2000 11:43 AM
> To: David Wang
> Cc: mpls@UU.NET
> Subject: Re: Ingress LER in LDP
> 
> 
> On Fri, Jun 02, 2000 at 01:20:33PM -0500, David Wang wrote:
> > One related question: How a LSR distinguishes a labeled packet from an
> > unlabeled packet? 
> 
> Depends on the medium:
> -ATM the VCC will contain a protcol type (AAL5Null requires this)
> -POS the ether type will be 0x8847 or 0x8848 (as oppsed to 0x0800 for IP)
> -PPP has some PIDs assigned for MPLS as well (as does IP)
> 
> Hope this helps.
> 
> Jim
> 
> > 
> > -----Original Message-----
> > From: Eric Rosen [mailto:erosen@cisco.com]
> > Sent: Thursday, June 01, 2000 9:28 AM
> > To: Santosh Gupta
> > Cc: mpls@UU.NET
> > Subject: Re: Ingress LER in LDP 
> > 
> > 
> > Santosh> Can someone tell me how to decide if a router is 
> supposed to act as
> > Santosh> an Ingress LER for some particular FEC in MPLS domain ?
> > 
> > People keep asking  this question, and I'm never quite sure  
> just what it is
> > they are asking, because there isn't much of a mystery here.
> > 
> > If a router received an unlabeled  packet which belongs to a 
> particular FEC,
> > and the next hop for that packet supports MPLS, and the router 
> is configured
> > such that it is allowed to do allow label imposition for 
> packets in that FEC
> > with that next hop, then the router should impose the label 
> assigned to that
> > FEC by that next hop.
> > 
> > Does that answer your question? 
> 
> -- 
> James R. Leu
>