The MPLS WG Archive

["Morgan, Richard" <rmorgan@orchestream.com>]

Does the Virtual Router soluntion take advantage of the 'hierrachy of
routing knowledge' ie use two labels, one to get the PE and another to
identify the VR - or does it create individual LSP's between each other VR's
and not use the label stack ?

Richard Morgan

> -----Original Message-----
> From: Hamid Ould-Brahim [mailto:hbrahim@nortelnetworks.com]
> Sent: Thursday, October 26, 2000 4:17 PM
> To: Paul Tasillo
> Cc: mpls@UU. net; nbvpn@bbo.com
> Subject: Re: FW: VPN solution - White flag ?
> 
> 
> Paul,
> 
> Your scalability question is really related to PE's resources 
> (e.g., CPU,
> memory)
> On this respect building vpns with virtual routers is
> no different than any other application
> 
> VPN/PE scalability depends also on factors like the software/hardware
> architecture of the PE and  whether the "virtualization" 
> aspect of VR is
> built in within the PE infrastructure day one.
> 
> However no matter how powerful is the PE, there is always a limit
> on what you can do on it.
> 
> Regards
> Hamid
> 
> 
> Paul Tasillo wrote:
> 
> > Will the overhead of running Virtual Routers impact the 
> scalablity of the
> > draft-ouldbrahim-vpn-vr-01 approach? That is, there must be 
> a limit to the
> > number of VRs a PE can handle and thus a limit to the 
> number of VPNs the PE
> > can handle. Is this true?
> >
> > -Paul (not Paul Doolan)
> > Paul Tasillo
> > Tivoli Systems
> >
> > -----Original Message-----
> > From: owner-mpls@UU.NET [mailto:owner-mpls@UU.NET]On Behalf Of Jim
> > Guichard
> > Sent: Thursday, October 26, 2000 8:43 AM
> > To: Barry Hass; erosen@cisco.com; Paul Doolan
> > Cc: yakov@cisco.com; rnewcomb@ennovatenetowrks.com.tivoli.com;
> > mpls@UU.NET; diego@estos.upc.es
> > Subject: RE: VPN solution - White flag ?
> >
> > Barry,
> >
> > the answer is no. There are various ways to design Internet 
> connectivity
> > within this environment, one of which is to carry full 
> Internet routes on
> > the PE router. Other options include default routing from 
> VPN sites to a
> > central site that has Internet connectivity, another is to 
> offload the
> > Internet routes from the PE and run direct eBGP sessions 
> from the VPN site
> > to the Internet exit point. Which option is actually taken 
> will depend on
> > the specific design requirements. Jim
> >
> > At 08:37 26/10/2000 -0400, Barry Hass wrote:
> > >Eric,
> > >
> > >Doesn't a PE router have to handle the full Internet routing
> > >table, plus VRFs for whatever VPNs it is supporting? I think
> > >that what some folks are suggesting is that BGP (not "the box",
> > >but BGP specifically) is already bumping up against scaling
> > >limits at 100,000 or so routes, and that burdening it with the
> > >additional responsibility of managing VPNs is not such a great
> > >idea. ("Some folks" please correct me if I'm wrong). Can you
> > >comment on that?
> > >
> > >By the way, I don't have enough information to have an opinion
> > >on this. I'm just trying to steer the discussion back to what
> > >I thought was an interesting technical question before the
> > >insults started to fly.
> > >
> > >> In the  NBVPN routing environment, it is  not true that
> > >> anyone  in the world
> > >> needs to be  able to reach anyone else  in the world.  Each
> > >> VPN  has its own
> > >> inter-connectivity  matrix,  much  smaller  than the
> > >> Internet  connectivity
> > >> matrix.  Now if you add up all the VPN routes, summed over
> > >> all VPNs, you may
> > >> indeed get  a much larger  number than the  number of
> > >> Internet  routes.  But
> > >> there is no one box which needs  to hold them all.  Since an
> > >> instance of BGP
> > >> runs in a particular box, and only  has to deal with the
> > >> routes that need to
> > >> be in that box,  you don't run up against the same  box
> > >> scaling problems you
> > >> run up  against in  the Internet routing  environment.  You
> > >> can  design your
> > >> system to  have a given box  handle as many routes  or as few
> > >>  routes as you
> > >> want.
> > >
> >
> > Jim Guichard CCIE #2069
> > Network Design Consultant EMEA
> > Global Solutions Engineering
> >
> > +44 208 756 8806
> > Mobile: +44 7802 809763
>