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Counter Braids A Novel Counter Architecture for Per-Flow Measurement (sigmetrics 2008) . Yi Lu Andrea Montanari Balaji Prabhakar Sarang Dharmapurikar Abdul Kabbani. Measurement in high capacity. A large number of counters.
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Counter Braids A Novel Counter Architecture for Per-Flow Measurement (sigmetrics 2008) Yi Lu Andrea Montanari Balaji Prabhakar Sarang Dharmapurikar Abdul Kabbani
Measurement in high capacity • A large number of counters. • A large number of flow to counter association rules are also required. • Need to combine counters in a efficient and a decodable manner.
Counter Braids • Combine counters to build a braid like structure. • Optimum since maximum asymptotic compression rate is achieved. • A low complexity decoder with zero errors.
Execution • Run algorithm in epochs (e.g. of 5 mins). • Packets are counted (not bytes). • Graph is updated dynamically. • At the end of the epoch decoding algorithm is run the to find out the count for each flow.
Solution • Counters arranged in one of more levels. • A small number of hash functions to map flows to level 1 counters. • More hash functions to map between each two layers.
Optimum solution • 2 layers are usually sufficient. • 3 hash functions is optimum for two layers. • Layer 1 depth should be 5 to 8 bits layer two should be larger. • Status bits are helpful.