In the Nokia Service Router Operating System (SR-OS), Quality of Service (QoS) for traffic heading into the network core is managed by network QoS policies. Specifically, a network-queue policy is applied to the egress context of a network port. This policy defines the set of queues, their characteristics (e.g., CIR, PIR), and how traffic, based on its Forwarding Class (FC), is mapped to these queues.

Since traffic from both the VLL (epipe) service and the VPLS service on router PE B must exit through the same physical network port to reach PE A, all of this traffic will be subjected to the single network-queue policy configured on that egress network port. The policy is associated with the network port itself, not the individual services that are forwarding traffic through it.

The alternative, False, is incorrect. It would imply that network-queue policies can be applied on a per-service basis for network-bound traffic. This is not how the SR-OS QoS model is designed. While service-level QoS policies are applied at the Service Access Points (SAPs), the aggregation and queuing of traffic from multiple services onto a network link are handled by a single, port-level network-queue policy.

1. Nokia 7750 SR OS Quality of Service Guide, Release 21.x.R1.

Section: Network QoS Policies > Network Egress

Content: The documentation states, "Network egress QoS policies are applied to network ports, channels, and portal ports to define queuing and scheduling for traffic transmitted into the service provider network core." It further clarifies that a network-queue policy is assigned to a network port's egress context (config>port>ethernet>network>egress). This confirms the policy is a port-level construct, and therefore, all traffic from any service using that port for egress will be handled by the same policy.

2. Nokia 7750 SR OS Services Architecture Guide, Release 21.x.R1.

Section: Quality of Service (QoS) for Services > QoS Policy Entities

Content: This guide illustrates the QoS architecture, showing a clear distinction between service QoS policies (applied at SAPs) and network QoS policies (applied at network ports). Diagrams in this section depict traffic from multiple services converging on a network port, where a single network egress QoS policy is applied before the traffic is transmitted over the MPLS core. This reinforces that the VLL and VPLS traffic would be handled by the same network-queue policy on the egress port of PE B.