VBR

The service type Variable Bit Rate come in two variants: Non-Realtime VBR and Realtime VBR.

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

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