Hop-by-hop loss control
- Goal: control the (short-term) loss pattern for a (VoIP) flow
- Constraints:
- do not change the loss rate (intra-flow QoS)
- do not reorder packets
- Observation: queue management like RED already influences the loss pattern (reduces the burstiness)
- “Differential” RED (DiffRED; distributed approach):
- sender marks packets according to recoverable loss pattern (a0p0 + a+1p+1 + a-1 p-1 = ap0 a+1 = a-1)
- network enforces the pattern (p-1 = 2 p0 - p+1) ax, x ? [-1, 0, +1]: number of packets marked as x, 0: best effort px, x ? [-1, 0, +1]: drop probability