We have 2 4500x switches with Ent Services licences. The plan is to replace the current core routers with a L3 switched core using the 4500x with VSS. The core will connect 3 building data closets, a local data center and 18 remote WAN sites. Engineering the remote sites is where I need some advise.
The in place design has fiber from each remote site connected to a 1 gigabit interface on a Ciena L2 distribution switch. The Ciena switch is connected to the core router via a gigabit Ethernet interface. The interface on the router is divided into 18 sub interfaces one for each branch. Each sub interface has a service policy that shapes the traffic to varying bandwidths in increments of 10mbps up to 50mbps.
The proposed design involves connecting the the Ciena switch to the 4500x VSS pair using 2 10 gigabit Ethernet interfaces. The connections to the Ciena would be L2 and the 4500x would have SVIs for each branch connection. The problem is that the 4500x does not allow traffic shaping on an SVI. Also you can not configure sub interfaces on a routed interface on the 4500x.
Since the Ciena will be connected to the core via 20Gbps would it be necessary to shape traffic to the core from the remote sites? The only concern I have regarding not shaping traffic is that there is a potential to oversubscribe other segments of the network like the data center and the internet link.
Is there another way that we can shape traffic to remote sites? I was thinking if we put a router between the 4500x and the Ciena this would work but I would have to get a pretty beefy router to support 20Gbps.