In the 7450 ESS and 7750 SR service model, the service edge routers are deployed at the provider edge. Services are provisioned on the routers and transported across an IP as well as an IP and MPLS provider core network in encapsulation tunnels created using Generic Router Encapsulation (GRE) or MPLS Label Switched Paths (LSPs).
The service model uses logical service entities to construct a service. The logical service entities are designed to provide a uniform, service-centric configuration, management, and billing model for service provisioning. Some benefits of this service-centric design include:
Many services can be bound to a single customer.
Many services can be bound to a single tunnel.
Tunnel configurations are independent of the services they carry.
Changes are made to a single logical entity instead of multiple ports on multiple devices. It is easier to change one tunnel instead of several services.
The operational integrity of a logical entity (such as a service tunnel and service end points) can be verified instead of dozens of individual services improving management scaling and performance.
A failure in the network core can be correlated to specific subscribers and services.
QoS policies, filter policies, and accounting policies are applied to each service instead of correlating parameters and statistics from ports to customers to services.
Service provisioning uses logical entities to provision a service where additional properties can be configured for bandwidth provisioning, QoS, security filtering, accounting or billing to the appropriate entity.