Dear Nanog community We are currently experimenting TCP degradation issues in some metro markets where there are multiple POPs and the IP packets have to pass multiple L3 access devices (routers) before reaching the core router. The more L3 hops that it goes through the more degradation we see in the Internet service. L3 routers have the capacity in terms of pps and BW and we are using just a small percentage of that capacity but anyway the service is degraded (No CRC/Input errors in the links). A couple of vendors are recommending using OTN or MPLS-TP to backhaul the connections from the access to the core but obviously deploying OTN means a considerable amount of capex. The flexibility and simplicity of the L3 based access network is great but given the performance issues we are experimenting I would appreciate if you can share your experience/recommendation with either OTN or MPLS-TP. Does it really make sense to use a OTN/Photonic layer to backhaul the L3 connections in a metro network? Your input is greatly appreciated Thanks and have a great day