RT-VBR: Specified
by the ATM Forum for services with stringent timing requirements (”real-time
applications”), like CBR but for variable bit rate services, e.g. compressed speech.
NRT-VBR: Specified by the ATM Forum for variable bit
rate services
without stringent timing requirements (”non-real-time applications”).
In both VBR service categories, we need to specify
the following traffic parameters:
- Peak Cell Rate (PCR)
- Sustainable Cell Rate
(SCR)
- Maximum Burst Size (MBS)