Subject: Re: [PWE3] MPLS PID

From: Curtis Villamizar <[email-masked]>
Date: Wed, 02 Apr 2003 09:34:06 -0500

In message <[email-masked]>, Luca Martini writes:
> 
> 
> Shahram Davari wrote:
> > I agree with Lloyd. Sniffing IP packets in the middle of an MPLS network is
>  fundamentally wrong, and is impossible to do for all ECMP implementations su
> ch as the one that I described
> > in earlier emails in which both the first nibble and the CRC are used to de
> tect IP.
> > 
> Shahram,
> It might be fundamentally wrong but this is deployed today , and we run our 
> hole network based on this little point. It seems to work fine for a network 
> that transport 90gb/s to 100Gb/s of actual traffic.
> 
> So if we put the theory, and layer arguments aside , what is the issue with 
> determining that a particular flow is not IP ( assuming IP = 99% of traffic )
>  ?
> 
> Luca
> 
> It might be fundamentally wrong
> 
> 
> > The best way to solve this problem is to do ECMP only based on label stack.
>  Doing so should be
> > easier than introducing new standard.
> > 
> > -Shahram

Solving real world problems is never fundamentally wrong.  If all
traffic is know to be either IP or contain a control word then there
is no chance of reorder so its not wrong at all.

Curtis