Downlink Forwarding Queues and Forwarding Classes

Downlink Forwarding Queues

Each anchor Packet Forwarding Engine is equipped with a set of 8 queues on the VRF Loopback interface (lo0). All mobile subscriber traffic on the anchor Packet Forwarding Engine traveling downlink will use these queues. These queues allow for service differentiation of your mobile subscriber traffic. The Downlink Forwarding Queues are preconfigured with default names and attributes, but you can manage the queues individually with one of these two commands:

To view your queue details, use the command show services mobile-edge anchor class-of-service.

VRF Loopback Queue Assignment

A downlink forwarding queue/class is assigned to each bearer/service data flow (SDF). Assignment depends on whether your network has provided Transport Level Marking (TLM) within the forwarding action request (FAR).

• TLM Provided: If TLM is included with the FAR, then the TLM DSCP value maps mapped to a forwarding class that is using a configured classifier.

• TLM Not Provided: If TLM is not included with the FAR, the GBR-LOW queue/class is assigned to the Guaranteed Bit Rate (GBR). The BE-LOW-0 queue gets assigned to the non-GBR bearer/SDF.

  See downlink-dscp-to-forwarding-class for more information.

WAN Egress Forwarding Class Assignment (5G Only)

You can configure a WAN Egress Classifier for the User Plane Function (UPF). This classifier maps DSCP codes from the FAR's TLM to the forwarding class assigned to the packet. This classifier then selects the specific egress queue to use on the WAN interface. You use the downlink-dscp-to-egress-forwarding-class command to configure the WAN egress classifier.

The Egress Forwarding class gets assigned to the SDF. All packets matching that SDF inherit the forwarding class. If the Egress Forwarding Class is not assigned to the SDF, existing forwarding class assignments are unaffected.

See downlink-dscp-to-egress-forwarding-class for more information.