Hi Fred, I think a lot of the confusion here comes from the fact that you're using generic terms like "switching" and "VLAN" to describe complex Metro-E/Carrier-E scenarios. Standard VLANs break up broadcast domains, but they don't create virtual circuits or provide total isolation - this is one of the reasons I initially asked what you were describing. Metro-e q-in-q with stag/ctag UNIs and EVCs behave much differently than standard packet switched ethernet "dot1q" VLANs in that regard. I'd reference the different metro-e IEEE standards if I were smart enough to keep them all in my head or unlazy enough to look them up.
Tons of info available at metroethernetforum.org for folks who are trying to figure out what I'm talking about. I'd be extremely impressed to learn that you could do a decent metro-e roll-out with ubnt and mt. In the WISP world, I'd expect single-tagged dot1q VLANs to be enough to differentiate customer traffic, even in large-ish MPOP scenarios. How many POPs generally hang off a single network segment before hitting a router? Thanks for the interesting discussion! TD On 10/12/2012 10:14 PM, Fred Goldstein wrote: > I'm not sure we're talking about the same thing. It is allowing only > the VLAN to go from A to B, while nothing else goes to A or B, and the > VLAN is invisible to everyone else. Which is really virtual circuit > behavior; VLAN is the legacy name of the VC ID. > > In CE switching, then, the VLAN receives no broadcasts from anyone > else on the switch or network, and sends no broadcasts outside. What > goes onto that mapped port, or onto a VLAN pre-tagged to go to that > port, is totally and completely invisible to all other users. So it's > secure enough for public safety use on a shared PMD. This is > different from a bridge, where broadcasts go everywhere. One type of > MEF service (EP-LAN) does actually emulate a LAN with >2 ports and > broadcasts among them, but the more common EPL and EVPL would not know > a broadcast frame from anything else, since they just pass the MAC > addresses transparently. _______________________________________________ Wireless mailing list Wireless@wispa.org http://lists.wispa.org/mailman/listinfo/wireless
