QBone Scavenger Service (QBSS)
Provides two classes of service:
- default class (best-effort)
- scavenger class (less than best-effort)
Link capacity is split between classes.
A small portion of network capacity is allocated for scavenger class.
When the default best-effort capacity is underutilized, QBSS can expand to consume unused capacity.
Scavenger class is not identical to low priority class.
Classifying some flows as scavengers improves QoS received by flows in default class.