An engineer is designing a QoS solution for a campus.

The design should use a scavenger queue for excessive or suspicious traffic and apply queuing on the access-to-distribution uplinks where congestion can occur. Cisco QoS campus design commonly uses a less-than-best-effort scavenger class to constrain traffic associated with worms, peer-to-peer applications, bulk background flows, or other nonbusiness traffic. Placing this traffic in a scavenger queue minimizes the bandwidth it can consume during congestion without harming real-time applications. Real-time voice or video traffic should be placed in a strict-priority queue so it receives low delay and low jitter treatment when links are congested. Applying queuing on access-to-distribution links is important because those uplinks are common campus congestion points, especially during bursts or abnormal traffic events. A shaping policy is not the right tool for campus LAN uplinks, and indiscriminate policing of real-time traffic can cause drops that damage voice and video quality. Reference topics: campus QoS, scavenger class, strict-priority queue, access uplink queuing, congestion management, worm mitigation.