Network Researchat

Avaya Labs Research

The ExpertNet and Chatter Teams

Akshay Adhikari

Mark Bearden

Lorraine Denby

Bengi Karacali

Jean Meloche

Balaji Rao

David Stott

Among many others

Challenges

• Network topology discovery

• Heisenberg

– Probes load the network at the worst time

– Path or end to end performance but not both

• Visualizations for paths

– Topology and paths

– Route changes

• Synchronization and One way delay

• Load balancing and packet loss

• Missing values and clean up

• Complexity of networks

• Volume of data (GB per day)

Discovery via the fusion of multiple data sources

• SNMP• IP RR• Traceroute• I/O octet count correlation• Delay distance• End to end shadow of network events

Synchronization

Link level network delay via TTL flood

• Multiple packets with IP RR for a range of TTL are sent between endpoints

• ICMP messages are received from routers along the way

• Results are used to estimate link level delays

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Network Sampling Design

• Where to place the probes

– Minimize the number of probes needed

– Minimize the degeneracy

– Subject to many constraints

• Where to measure QoS attributes and covariates

– Minimize the footprint

– Minimize the time to blame

• Dynamic sampling programs

Chatter

• Distributed network monitor• Lives on cheap 100 MHz box• Online root cause analysis• Seeks failure patterns among arbitrary

covariates that are not specified a priori• Uses adaptive control charts on important

QoS attributes to identify interesting conditions

Compression

• Compression is needed to prevent the transmission and storage of uninteresting data

• The data are highly dimensional

• The collection is distributed

• How should the compression be distributed

Localization

• Data collection is distributed

• What methods are local (analysis requiring only the local data) or near local (analysis requiring limited exchange of information between neighbors)?

• Are there sampling design that affect localization?