# VBR

The [service type](/glossary/s/service_type) Variable Bit Rate come in two variants: Non-Realtime VBR and Realtime VBR.

## Non-Realtime VBR

Non-Real-Time Variable Bit Rate (nrt-VBR) is used for connections that need guaranteed [bandwidth](/glossary/b/bandwidth) or [latency](/glossary/l/latency), but do not rely on accurate timing between source and destination.

## Realtime VBR

Real-Time Variable Bit Rate (rt-VBR) is used for connections that need accurate timing between source and destination.