Techniques for virtualizing tenant transport interfaces configured to implement per-tenant network routing attribute differentiation in each tenant overlay of a multisite wide area network (WAN) and share the virtual transport interfaces between multi-tenant edge (MTE) devices providing transport services to tenant devices based on a defined tenant tier model. A Software-Defined Networking (SDN) controller may receive a physical transport interface and/or a device type associated with a tenant device. The SDN controller may determine a virtual transport interface for the tenant device based on a tier associated with the tenant. MTE device(s) may utilize the physical transport interface to establish sessions with other MTE device(s) in the WAN. The virtual transport interface may be utilized by MTE devices to implement and/or enforce network routing attributes when forwarding network traffic associated with the tenant via the sessions established between the MTE devices through the WAN.