Hello,
sorry for some kind of completly newbei question, we're starting a small IPS business and need some advice for our backbone platform.
We're getting some utagged and transparent Ethernet interfaces on each POP (may be 20-25 distributed over one country in Europe ), simple P-t-P fibre connection converted to Ethernet. Each POP has 2-5 connection to the other POPs in some kind of Partial-Mesh topology.
The idea is to configure 3 POPs with Internet upstreams, and other POPs only as access. The most of the customers need only Internet access, but some need VPN between the locations. At the first glance the choise is Metro-Ethernet on base of Q-in-Q tagging, but there is limitation of 4096 VLANs (means "only" 4096 customeres can get the VPN) and some MAC table limitatation. But the configuration is looking quite straightforward, on Access POP will be installed a pair of c3650E, on the "central" POPs pair of 3560E and pair of c7200, the "Internet" customers are getting a simple access port, VPN customerts getting tagging port.
The first question , what is better to use STP between all POPs or configure all inteconnection links as L3 on 3560 ? I think with L3 connection between all POPs it's more simple to manage the traffic, with STP blocked ports it's not really flexable.
Another possibility is MPLS backbone, but then is the question how to configure the L2 tunnel for the customers which need the L2 transparent service? As I understood VPLS are only supported on the c7600 with "special" linecard. But xconnect can be still used on the PE side and the L2 packets will transparently distributed via MPLS backbone, isn't?
Another thing, 3560E doesn't support MPLS natively and we can't use them as PE, isn't? 3750Metro could be OK, but I think the price is much higher.
Or may be one can do following: to use those 3 POPs with c7200 as MPLS backbone and configure c7200 as P and PE and use 3560E on sites as simple aggregate L2 links with L3 termination on those c7200, but the problem not all POPs has direct connection to the "central" POPs and it means that we'll get then mix from QinQ and MPLS backbone
I understand that these questions are quite "basic" but we don't have much practical experience with MetroE and MPLS in ISP backbone, currently it's just normal L3 core with normal L2 switches as aggregation in couple of POPs .
Best Wishes!
