Service egress QoS policies on 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12

Service egress queues are implemented at the transition from the service core network to the service access network and are available when SAP-based egress queues and shaping is enabled by using the configure system resource-profile qos no port-scheduler-mode command on the 7210 SAS-Mxp and the configure system global-resource-profile qos no port-scheduler-mode command on the 7210 SAS-R6 IMM-b and 7210 SAS-R12 IMM-b. The advantages of per-service queuing before transmission into the access network are:

Note:

The sub-rate capabilities and per-service scheduling control are required to make multiple services per physical port possible. Without egress shaping, it is not possible to support more than one service per port with QoS differentiation among services. There is no way to prevent service traffic from bursting to the available port bandwidth and starving other services.

For accounting purposes, per-service statistics can be logged. When statistics from service ingress queues are compared with service egress queues, the ability to conform to per-service QoS requirements within the service core can be measured.

Service egress QoS policies define egress queues and map FC flows to queues. The system allocates 8 (eight) queues to service egress by default. To define a basic egress QoS policy, the following are required:

The optional service egress QoS policy elements include specifying a remark policy that defines IEEE 802.1p priority value remarking based on FC.

The user has an option to use SAP-based marking. With SAP-based marking the remark policy defined in the SAP egress policy associated with each SAP is used to mark the packets egressing out of SAP if marking is enabled. See the Service egress policies on 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12 and the Remark policies for more information about marking behavior and the available options. The user can also enable port-based marking, in which case the remark policy defined in the access egress policy associated with the access port determines the marking values for all the SAPs defined on the port. See Access egress QoS policies on 7210 SAS-Mxp for more information.

Note:

Each queue in a policy is associated with one of the FCs. Each queue can have individual queue parameters allowing individual rate shaping of the FCs mapped to the queue. The FC per service egress packet is determined at ingress. If the packet ingressed the service on the same node, the service ingress classification rules determine the FC of the packet. If the packet is received, the FC is marked in the tunnel transport encapsulation.

The FC-to-queue map is fixed, and the queue priority is determined by the queue number, with the higher queue number having the higher priority. The user can configure a queue to be a strict queue to change the scheduling behavior for that queue. See Schedulers on 7210 SAS-Mxp and Schedulers on 7210 SAS-R6 and 7210 SAS-R12 for more information.

Note:

On the 7210 SAS-Mxp, only unicast traffic sent out of RVPLS SAPs uses per-SAP egress queues. BUM traffic sent out of RVPLS SAPs uses per-port egress queues.

Service egress QoS policy ID 1 is reserved as the default service for those that do not have another service egress policy explicitly assigned. The following table lists the characteristics of the default policy.

Table: Default service egress policy ‟default” definition
Characteristic Item Definition

Queues

Queue 1-8

1 (one) queue defined for each traffic class

Network-Control (nc)

Queue 8

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

High-1 (h1)

Queue7

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

Expedited (ef)

Queue 6

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

High-2 (h2)

Queue 5

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

Low-1 (l1)

Queue 4

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

Assured (af)

Queue 3

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

Low-2 (l2)

Queue 2

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1

Best-Effort (be)

Queue 1

  • CIR = 0

  • PIR = max (line rate)

  • queue-mgmt = default

  • queue-mode = weighted

  • weight = 1
Parent topic: Network and service QoS policies