Ring and non-ring buffer pool

When the 7210 SAS-K 2F1C2T is deployed in a ring environment, the access-uplink ports are typically used to connect the node to ring. Similarly, on the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, users will typically use the network ports to join the node into a ring. Therefore, these ports are designated as the ring ports. These ring ports carry traffic from the head-end toward the node (that is, the 7210 SAS), dropping traffic off to user/customer locations. Simultaneously, these ring ports carry traffic from the user/customer to the head-end. That is, traffic received from the user/customer is added to the ring and sent out toward the service edge, where services are terminated. The traffic in both these directions is typically admitted into the ring after being shaped and groomed. In the upstream direction (that is, in the direction of customer to service edge) the SLA is enforced at service ingress points (that is, typically access SAPs) and the traffic is shaped and groomed, similarly in the downstream direction (that is, in the direction of service edge to customer) it is done by the service edge device or the access aggregation device. That is, the downstream traffic should typically be allowed to pass through the intermediate nodes of the ring, without contention with and prioritized over the traffic that is received from the customer and being added into the ring by the nodes on the ring.

On the 7210 SAS-K 2F1C2T, the access-uplink ports are designated as ring ports and access ports are designated as non-ring ports. Traffic going from any access-uplink to another access-uplink port is identified as ring traffic. Traffic going from an access port to any access-uplink port, or traffic going from any access-uplink port to an access port (in egress), or traffic going from an access port to another access port is identified as non-ring traffic.

On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, the network ports and access-uplink ports are designated as ring ports and access ports are designated as non-ring ports. Traffic going from any network port or access-uplink to another network port or access-uplink port is identified as ring traffic. Traffic going from an access port to any network port or access-uplink port, or traffic going from any network port or access-uplink port to an access port (in egress), or traffic going from an access port to another access port is identified as non-ring traffic.

On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, the SAPs configured on hybrid ports are designated as non-ring service objects, and network port IP interfaces are designated as ring service objects. Traffic going from any network port IP interface on a hybrid port to another network port IP interface on a network port or a hybrid port, or the other way around, is identified as ring traffic. Traffic going from a SAP configured on a hybrid port to any network port, access-uplink port, or access port, or to another SAP on the hybrid port, or the other way around, is designated as non-ring traffic.

To ensure that the traffic received on ring ports is prioritized over traffic received on non-ring access ports, a separate ring MBS buffer pool (one each for ingress and egress) is provided for traffic received and sent out of ring ports. In addition, for ring ports and service objects, such as network port egress, hybrid port egress, and access-uplink egress (where shaped customer (access) traffic and ring traffic share the ring pool), two additional ring slopes (for a total of four configurable WRED slopes) are provided to prioritize the ring traffic. Each egress queue on the network port, hybrid port, or access-uplink port supports four slopes per queue — ring high-slope, ring low-slope, non-ring high-slope, and non-ring low-slope (in the CLI command, the ring slopes are configured using the high-slope-ring and low-slope-ring, and the non-ring slopes are configured using the high-slope and low-slope). Ring high-slope and ring low-slope are used for in-profile and out-of-profile QoS profile ring traffic. Non-ring high-slope and low-slope are used for in-profile and out-of-profile non-ring traffic. Slope parameters (start-avg, max-avg, max-prob) of four slopes can be configured such that the ring traffic is prioritized over the non-ring traffic (that is, traffic being added onto the ring) in congestion scenarios.

A separate non-ring MBS buffer pool for traffic received and sent out of access ports along with two configurable WRED slopes is supported. Each queue on the access ports supports two slopes per queue –non-ring high-slope and non-ring low-slope. Non-ring high-slope and low-slope is used for in-profile and out-of-profile non-ring traffic. The non-ring buffer pool (one each for ingress and egress) is used to allocate buffers for non-ring traffic.

The usage of buffer pools for different traffic flows is as follows.

On the 7210 SAS-K 2F1C2T, the ring and non-ring buffer pools are used by the following traffic flows:

On the 7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C, the ring and non-ring buffer pools are used by the following traffic flows:

Parent topic: Buffer pools