V-217080

Discussion

Different applications have unique requirements and toleration levels for delay, jitter, bandwidth, packet loss, and availability. To manage the multitude of applications and services, a network requires a QoS framework to differentiate traffic and provide a method to manage network congestion. The Differentiated Services Model (DiffServ) is based on per-hop behavior by categorizing traffic into different classes and enabling each node to enforce a forwarding treatment to each packet as dictated by a policy. Packet markings such as IP Precedence and its successor, Differentiated Services Code Points (DSCP), were defined along with specific per-hop behaviors for key traffic types to enable a scalable QoS solution. DiffServ QoS categorizes network traffic, prioritizes it according to its relative importance, and provides priority treatment based on the classification. It is imperative that end-to-end QoS is implemented within the IP core network to provide preferred treatment for mission-critical applications.

Check Content

Review the router configuration and verify that it has been configured to enforce a QoS policy in accordance with the QoS GIG Technical Profile (GTP-0009). The router must be configured to use either configured or default Behavior Aggregate (BA) classifier on all interfaces as shown in the example below:

class-of-service {
    …
    …
    …
    }
    interfaces {
        ge-0/0/1 {
            unit 0 {
                classifiers {
                    dscp default;
                }
            }
        }
        ge-0/1/0 {
            unit 0 {
                classifiers {
                    dscp default;
                }
            }
        }
        ge-1/0/1 {
            unit 0 {
                classifiers {
                    dscp default;
                }
            }
        }
        ge-1/1/0 {
            unit 0 {
                classifiers {
                    dscp default;
                }
            }
        }

Note: The GTP QOS document (GTP-0009) can be downloaded via the following link: 
https://intellipedia.intelink.gov/wiki/Portal:GIG_Technical_Guidance/GTG_GTPs/GTP_Development_List

If the router is not configured to enforce a QoS policy in accordance with the QoS GIG Technical Profile, this is a finding.