Asynchronous Transfer Mode: VBR and UBR
Variable Bit Rate (VBR)
Characterized by statistically expressed parameters
Guarantees mean cell transfer delay and cell loss ratio for traffic which remain within traffic contract
Support for real time and non-real-time burst sources
Unspecified Bit Rate (UBR)
Best Effort service
Transport of cells not necessarily guaranteed
Usable for some set of applications
Intended for delay-tolerant or non real-time applications