pathChirp Efficient Available Bandwidth Estimation

1
pathChirp Efficient Available Bandwidth
Estimation

• Vinay Ribeiro
• Rice University
• Rolf Riedi Rich Baraniuk

2
Network Model

• End-to-end paths
• Multi-hop
• No packet reordering
• Router queues
• FIFO
• Constant service rate

• Packet delay constant term
• (propagation,
• service time)
• variable term
• (queuing delay)

3
Available Bandwidth

• Unused capacity along path

Available bandwidth

• Goal use end-to-end probing to estimate
  available bandwidth

4
Applications

• Server selection

• Route selection (e.g. BGP)

• Network monitoring

• SLA verification

• Congestion control

5
Principle of Self-Induced Congestion
Probing rate lt available bw ? no delay
increase Probing rate gt available bw ? delay
increases

• Advantages
• No topology information required
• Robust to multiple bottlenecks
• TCP-Vegas uses self-induced congestion principle

6
Chirp Packet Trains

• Exponentially decrease packet spacing within
  packet train
• Wide range of probing rates
• Efficient few packets

7
Queuing Delay Signatures

• Goal exploit information in queuing delay
  signature

8
Internet Experiments

• 3 common hops between SLAC?Rice and Chicago?Rice
  paths

• Estimates fall in proportion to introduced
  Poisson traffic

9
Conclusions

• Chirp trains
• Probe at multiple rates simultaneously
• Efficient estimates
• pathChirp
• Self-induced congestion
• Excursion detection
• Experiments
• Internet experiments promising
• Outperforms existing tools
• More information spin.rice.edu