Dell SmartFabric OS10 User Guide Release 10.5.3

Quality of service

Enterprise networks carry various data traffic including voice and video traffic. To efficiently use the available network resources, Quality of Service (QoS) offers several features that help to:

• Allocate sufficient bandwidth for certain types of traffic, such as video traffic.
• Prioritize voice traffic.
• Transfer data reliably.
• Optimize performance.

QoS defines how reliable, available, and efficient a network is. Availability determines the quality of a network. Some of the factors that affect the quality of a network include:

• Delay—The amount of time it takes for a packet to reach the destination from the time the sender transmits it.
• Jitter—A difference in delay between two data packets.
• Loss—One or more data packets that are lost during transit in a network.
• Drop—One or more data packets that are dropped during transit in a network. Packet drop causes data loss.

Quality of service (QoS) reserves network resources for highly critical application traffic with precedence over less critical application traffic. QoS prioritizes different types of traffic and ensures quality of service.

You can configure QoS features on the switch to allocate sufficient bandwidth, offer lossless data transfer, prevent network congestion, and prioritize some traffic over others.

The following terms are used in this chapter:

• Ingress traffic—Traffic that comes in to the switch is called ingress traffic.
• Egress traffic—Traffic that leaves the switch is called egress traffic.

Different QoS features control the traffic flow parameters, as the traffic traverses a network device from ingress to egress interfaces.