network research at avaya labs research the expertnet and chatter teams akshay adhikari mark bearden...

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?