Low Latency Queuing (LLQ) adds a strict priority queue to CBWFQ. Voice gets absolute priority while preventing starvation.
How LLQ works:
- One class is strict priority
- Priority queue serviced first, always
- Priority has a policing rate limit
- Other classes use CBWFQ
Why police priority? Without a limit, priority traffic could starve everything. The police rate caps priority traffic at its expected maximum.
Typical design:
- Priority: Voice at % (policed)
- CBWFQ: Video at %
- CBWFQ: Critical data at %
- Default: Best effort gets %
LLQ is the standard for voice and video networks.