QoS - LLQ bandwidth configuration
In the context of QoS LLQ, the
bandwidth values you see in the
policy-map configurations relate to the actual speed or rate at which packets are sent out of the queue.
When you configure a policy map and specify a bandwidth for a particular class within the policy map, you are essentially telling the router to reserve that amount of bandwidth for that class under congestion conditions. It’s a way to guarantee that certain traffic (like voice or critical data) will have a certain amount of bandwidth available even when the network is busy. Remember, QoS is all about reserving and guaranteeing bandwidth for particular packets.
LLQ is specifically designed to provide strict priority queuing for delay-sensitive traffic like voice or video. The traffic that falls into the LLQ is given priority over all other traffic, up to the amount of bandwidth specified by the
priority command. This means that the LLQ will be served before other queues, and up to the configured rate, before other classes are able to send traffic.
bandwidth command in a
policy-map class specifies the rate at which packets are forwarded out of the queue.