What QoS step must occur before packets can be marked?

Before packets can be marked in a Quality of Service (QoS) process, they must be classified.

Classification is the step in QoS where packets are identified and categorized into specific traffic flows based on various criteria such as source and destination IP addresses, port numbers, or protocol type. This step is crucial as it determines how the network will handle these packets in subsequent QoS processes like marking, queuing, policing, or shaping.

Here’s a brief explanation of the other options:

• Queuing: This involves managing packets in queues based on their classification and marking. It comes after packets are marked.
• Shaping: This refers to adjusting the traffic rate of certain packets. Shaping usually occurs after classification and marking.
• Policing: This is the process of monitoring the rate of a flow and can result in re-marking or dropping packets that exceed a specified rate. Like shaping, policing typically happens after classification.