 In the specific context of an MPLS-based virtual private network (VPN), LERs that function as ingress and/or egress routers to the VPN are often called PE (Provider Edge) routers.Devices that function only as transit routers are similarly called P (Provider) routers.The job of a P router is significantly easier than that of a PE router, so they can be less complex and may be more dependable because of this.