[50813] in North American Network Operators' Group
Re: Do ATM-based Exchange Points make sense anymore?
daemon@ATHENA.MIT.EDU (Paul Vixie)
Fri Aug 9 22:34:37 2002
To: nanog@merit.edu
From: Paul Vixie <vixie@vix.com>
Date: 10 Aug 2002 02:32:11 +0000
In-Reply-To: <007201c23ff1$07703ea0$8c2a40c1@PHE>
Errors-To: owner-nanog-outgoing@merit.edu
> > What functionality does PVC give you that the ethernet VLAN does not?
>
> That=B4s quite easy. Endpoint liveness. A IPv4 host on a VLAN has no idea
> if the guy on the "other end" died until the BGP timer expires.
>=20
> FR has LMI, ATM has OAM. (and ILMI)
Adding complexity to a system increases its cost but not nec'ily its value.
Consider the question: how often do you expect endpoint liveness to matter?
If the connection fabric between your routers has an MTBF best measured in
hours or days, then you've got bigger problems than you'll solve with LMI.
If on the other hand the MTBF is best measured in months or years, then when
it does fail the failure is likely to be *in* the extra complexity you adde=
d.
--=20
Paul Vixie
