[c-nsp] Assigning VLANs on a per-subnet basis

[Robert Blayzor]

Frank Bulk wrote:
> At this point I have to admit my ignorance.  I'll have to talk to the P.E.
> at our consultancy to find out if an RPR without VLAN tags (or with just one
> VLAN tag) acts like a hub or if it does have the intelligence that you're
> describing.  


I think the big misconception is that RPR is just an ethernet handoff.
The only part of that is true is the port you're connecting to the
network with, in your case 100BaseTX/FX.

Again, I really only have experience with RPR on the Cisco platforms,
mostly being the ONS15454 via the ML card.  If you look at the ML card
it's basically a layer3 switch on a blade that has two virtual POS ports
that tie the card into the SONET network.  I guess that's where the ML
shines because you then have the flexibility to route or bridge over the
SPR interface (RPR interface to the ML card).

I guess where I'm getting confused is that you're the customer, I'm
looking at it from the transport side.  If four ISP's came to me and
wanted to use a packet ring and have an aggregation point where they can
share the entire alloted bandwidth they can be VLAN tagged (internal to
the transport provider) and then each customers interface would exist in
that VLAN.  Customers could then use a common subnet and route to each
other and the upstream.  It's a really easy application.

The ML will also do QinQ if you needed to do your own tagging around the
ring.  Another plus on the ML is that you can use service policies to
rate-limit traffic at each customers port, should you need to do that.

-- 
Robert Blayzor, BOFH
INOC, LLC
rblayzor\@(inoc.net|gmail.com)
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