IXP - PNI

Fri Apr 17 22:12:15 UTC 2009

On Fri, Apr 17, 2009 at 04:52:53PM -0500, Joe Greco wrote:
> > On Fri, 17 Apr 2009, bmanning at vacation.karoshi.com wrote:
> > > the vlan tagging idea is a virtualization of the PNI construct.
> > > why use an IX when running 10's/100's/1000's of private network
> > > interconnects will do?
> > >
> > > granted, if out of the 120 ASN's at an IX, 100 are exchanging on
> > > average - 80KBs - then its likley safe to dump them all into a single
> > > physical port and vlan tag the heck out of it.
> > >
> > > its those other 20 that demand some special care.
> > 
> > The construct also doesn't scale well for multicast traffic exchange if 
> > there's a significant number of multicast peers even though the traffic 
> > might be low for individual source ASNs.  On the other hand, if the IXP 
> > doesn't use IGMP/MLD snooping capable switches, then I suppose it doesn't 
> > matter.
> 
> Didn't we go through all this with ATM VC's at the AADS NAP, etc?
> 
> ... JG

	yes indeed.

--bill