What's the frequency of the letter "m" in:
Q: RSTP over tunnel? tl;dr: Is it possible to run RSTP over l2tp or MPLS?
We have leased one gig capacity from a service provider's network, over which we sent a udp multicast traffic. The provider gives us drop at our PoPs at different locations and we terminate the link in our switch at each PoP. The provider uses a ring topology and if there is any cable cut or similar problem the traffic will be routed over the other path. But there are times when their are multiple cuts in the ring and we loose the connectivity entirely.
We also have another dark fiber leased from another provider, which does not have the coverage of the first provider, but still reaches major PoPs, and is terminated in the same switch as the first provider.
Currently if the first provider network is down, we manually switch to the second provider. Obviously this is suboptimal. What we need is that if the first provider ring fails, traffic automatically switches to the second provider. The challenge is that the first provider is running their own switches and has some sort of redundancy protocol running for ring management. They are not willing to give us information about the configuration of their network and are not willing to cooperate with us to configure RSTP. 
What options do we have in this scenario? I would imagine we running a tunnel (l2tp/mpls)? between our switches connected to the first provider and all our traffic flows through the tunnel and configure RSTP across our switches. Is some thing like that possible? Do we have any other alternative solution.
We are now using low end switches at PoP, and can buy necessary gear if we have a solution.

A: Unless it is absolutely necessary, which I doubt, running layer-2 over a WAN is a really bad idea. STP will require all sorts of tweaks to work correctly with the increased latency. You need to measure the latency and apply it to all the STP calculations. Broadcasts, multicasts, and unknown unicasts will need to travel end-to-end to every switch port in the layer-2 domain which eats expensive WAN bandwidth. Layer-3 will control the broadcast and unknown unicast traffic, and PIM and IGMP will make sure that multicast is delivered only to those routers, switches, and switch ports which request the multicast group traffic.
You may be thinking that multicast traffic needs to have layer-2 all the way through, but that is not really the case. You can use layer-3 and multicast routing as a far more stable situation.
Almost nothing today needs to have end-to-end layer-2; we live in a layer-3 world. The old adage of, "Switch where you can, route where you must," has been completely turned on its head. It is now even recommended to run layer-3 all the way to the access switch. Layer-3 switches are now quite advanced and less expensive than they used to be.
You should really think about using layer-3 tunnels instead of layer-2 tunnels.

user
I counted 39 "m"s in that text.
assistant