This feature is only supported on 7210 SAS-T operating in access-uplink mode.
On the node where the service originates, in addition to the access dot1q range SAP, the service needs to be configured with access-uplink SAPs on the two G.8032 ring ports. G.8032 mechanism is used to for breaking the loop in the ring and VPLS service protection. The intermediate nodes on the ring needs to use VPLS service with access-uplink SAPs on the ring ports and use the same G.8032 instance for protection, as one is used for service protection on the originating node.
The following figure shows how two business offices, served by an operator are connected in a ring network deployment using Dot1q range SAPs and a VPLS service with G.8032 for protection.
The following are the requirements to provide for an Epipe service connectivity between two business sites:
Transport all the VLANs used by the internal enterprise network of the businesses.
Support high availability for the service between the business sites by protecting against failure of the links or nodes in the ring.
To achieve connectivity between two business sites in access-uplink/Layer 2 mode is to configure SAPs for each of the individual VLANs used in the enterprise network in a VPLS service and use G.8032 for protection. The number of VLANs that was supported is limited by the number of SAPs supported on the platform.
The 7210 SAS platforms, currently support the use of Dot1q range SAPs with only Epipe services in either network/MPLS mode or access-uplink/Layer 2 mode. Dot1q range SAPs allows operators to transport a range of VLANs by providing similar service treatment (service treatment refers to forwarding decision along with encapsulation used, QoS and ACL processing, accounting, etc.) to all the VLANs configured in the range. It simplifies service configuration and allows operators to scale the number of VLANs that can be handled by the node. This took care of the need to support hundreds of VLANs using a single SAP or a small number of SAPs. When MPLS the mode is deployed in ring topology, operators have the option of using different redundancy mechanisms such as FRR, primary/secondary LSPs, Active/Standby PWs, to improve Epipe service availability. No such option is available to protect Epipe service in Layer 2 mode when deployed in a ring topology. Additionally many operators prefer G.8032 based ring protection mechanism, since a single control instance on the ring can potentially protect all the VPLS services on the ring.
This feature allows operators to deploy Epipe services in a ring topology when using Layer 2 mode, by emulating an Epipe service using a VPLS service with G.8032 protection and at the same time provides the benefits of using dot1q range SAPs. The user should ensure that the VPLS service is a point-to-point service. This is achieved by configuring a VPLS service with an access dot1q range SAP used at the customer handoff on one node in the ring and an access dot1q range SAP in a customer handoff of a VPLS service on another node (that is, at the other end of the Epipe), such that there are only two endpoints for the service in the network.
On the node where the service originates, in addition to the access dot1q range SAP, the service needs to be configured with access-uplink SAPs on the two G.8032 ring ports. G.8032 mechanism is used to for breaking the loop in the ring and VPLS service protection. The intermediate nodes on the ring needs to use VPLS service with access-uplink SAPs on the ring ports and use the same G.8032 instance for protection, as one is used for service protection on the originating node.