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Network Research. An Operator’s Perspective Terry Gray University of Washington Associate Vice President, Technology Engineering, C&C Affiliate Professor, CS&E Microsoft EdgeNet 01 June 2006. Theme. "Every day's a winding road" -S. Crow
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Network Research An Operator’s PerspectiveTerry Gray University of Washington Associate Vice President, Technology Engineering, C&C Affiliate Professor, CS&E Microsoft EdgeNet 01 June 2006
Theme • "Every day's a winding road" -S. Crow • "Every day's a research experiment" -T. Gray
Questions • Seen any 404s go away by themselves lately? • Is the trend getting better or worse? • What is the max retry count in MS Windows? • TcpMaxDataRetransmissions = ? • Could there be a connection?
Thesis • The (open) Internet died in 2003 at the hands of slammer and blaster • It's no longer about pervasive connectivity…now it’s all about (selective) isolation • Tolerance for, and frequency of, glitches.. is increasing • Current Internet model is busted… e.g. silent failures, poor diagnostics
Buzz Words • trust-mediated transparency • convergence/virtualization
Miscellany • Perimeter Protection Paradox • Good ol' days of the network utility model • Defense-in-Depth vs MTTD, etcClaim: • M-T-to-penetration, innovation, diagnosis ~ d**2 • How many arbitrary PEPs before the overall system becomes non-deterministic?
Trends • Software-defined networks • Personal lambdas • Port 80/443 tunneling to get thru firewalls • Encryption • End-point firewalls (changes diagnostic picture) • More policy boundaries; less effective • Regulation/compliance
Imagine • Being in a NOC with an irate customer on the phone: • Customer: "Is the network broken?" • NOC: "I give up, is it?“
Hard problems • DDOS • Worsening MTTG • Diagnosis complexity (MTTD) • Provisioning complexity (vs. network utility) • Mismatch between best and common deploymente.g. tcp retry count, duplex mismatch, stack-tuning • S/N ratio of behavioral IDS monitors • Path policy discovery • Trust management • Policy enforcement is silent; looks like net failure
Hard problems (cont’d) • Managing heterogenity: bugs, conventions (jumbos) • Organizational vs. geographic topologies • Scaling personal lambdas • Managing/diagnosing with e2e encryption • Exception management • Seduction of more protocols (e.g. MTR) • Attribution vs. anonymity • Multicast fault containment • Optimal fault-zone sizing
Conclusions • Plenty of work to do • Help needed now! • Current problems must inform future/clean-slate proposals