A service is a globally unique entity that refers to a type of connectivity service for either Internet or VPN connectivity. Each service is uniquely identified by a service ID and an optional service within a service area. The 7210 SAS-series service model uses logical service entities to construct a service. In the service model, logical service entities provide a uniform, service-centric configuration, management, and billing model for service provisioning.
On the 7210 SAS-D, 7210 SAS-Dxp, and 7210 SAS-K 2F1C2T platforms, services can provide Layer 2/bridged service between a service access point (SAP) and another service access point (a SAP is where traffic enters and exits the service) on the same (local) router. It cannot support distributed services using MPLS uplinks.
On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C platforms, services can provide Layer 2/bridged service or Layer 3/IP routed connectivity between a service access point (SAP) on one router and another SAP (which is where traffic enters and exits the service) on the same (local) router or another router (distributed). The use of either MPLS uplinks or Ethernet uplinks is supported.
The 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C support both local and distributed service. A distributed service spans more than one router. Distributed services use service distribution points (SDPs) to direct traffic through a service tunnel to another Nokia router. SDPs are created on each participating router, specifying the origination address (the router participating in the service communication) and the destination address of another router. SDPs are then bound to a specific customer service. Without the binding process, the far-end router is not able to participate in the service (there is no service without associating an SDP with the service).