Cisco QoS Models

Campus LAN QoS

Classification and marking at the access layer; LLQ for voice and CBWFQ for data; trusts markings from IP phones and re-marks others as needed.

WAN QoS

LLQ for real-time traffic, CBWFQ for classes, traffic shaping outbound to match carrier rate, and WRED for TCP-heavy queues.

Metro-Ethernet QoS

Shape traffic to purchased CIR, preserve CoS/DSCP markings, and apply LLQ only where necessary.

Data Center QoS

Use DCB (Data Center Bridging), including PFC for lossless traffic, ETS for bandwidth allocation, and QoS marking for storage flows.

Service Provider QoS

Ingress policing on PE interfaces, MPLS EXP bit marking, hierarchical QoS in aggregation, and WRED in core routers.

Wireless QoS (WLAN)

WMM four-category prioritization, QoS mapping at the AP, call admission control for voice, and CAPWAP QoS marking support.

IPsec VPN QoS

Use QoS pre-classify to inspect inner headers, apply shaping, LLQ for voice, and copy DSCP values into IPsec tunnels.

Hybrid WAN / SD-WAN QoS

Application-aware routing, per-tunnel QoS, dynamic path selection using loss/latency/jitter metrics, and SaaS optimization.

Voice QoS (General)

Use LLQ strict priority queue, mark voice RTP with EF (DSCP 46), and guarantee low latency, jitter, and loss.

Cloud Direct Connect / ExpressRoute QoS

Trust provider markings, map CoS levels to cloud circuits, and maintain enterprise QoS models across private cloud links