
The infographic helps decide between private infrastructure and a telco service. The decision tree paths lead to (1) OTN mesh, (2) Traditional leased line (OTN, SONET/SDH, DWDM), (3) Layer 2 point-to-point VPN or, (4) Layer 3 VPN.
http://www.ciena.com/connect/blog/Infographic-The-WAN-infrastructure-decision-tree.html