Quality of Service overview

Quality of Service (QoS) provides preferential treatment to specific traffic.

Quality of Service (QoS) features are used to prioritize the use of bandwidth in a switch. When QoS features are enabled, traffic is classified as it arrives at the switch, and processed through on the basis of configured priorities. Traffic can be dropped, prioritized for guaranteed delivery, or subject to the delivery options as configured by a number of different mechanisms.

Classification is the process of selecting packets on which to perform QoS, reading or ignoring the QoS information, and assigning a priority to the packets. The classification process assigns a priority to packets as they enter the switch. These priorities can be determined on the basis of information contained within the packet or assigned to the packet as it arrives at the switch. Once a packet or traffic flow is identified and marked, then it is mapped to a forwarding priority queue.

Packets on Ruckus devices are classified in up to eight traffic classes with values from 0 to 7. Packets with higher priority classifications are given a precedence for forwarding.

There are two traffic types in QoS:
  • Data—These can be either network-to-network traffic or traffic from the CPU. QoS parameters can be assigned and modified for data traffic. The device also supports setting or modifying the IEEE 802.1p user priority or the IP header DSCP field..
  • Control—Packets to and from the CPU is considered control traffic. The QoS parameters associated with the control traffic are preassigned and not configurable.