Diverse Network Services and Remaining Challenges

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Diverse Network ServicesandRemaining Challenges

• SRCCS Winter 2005
• Workshop on
• Internet Modeling and Analysis
• Sue B. Moon
• Division of Computer Science
• Dept. of EECS
• KAIST

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Diverse Data Sets in Korea

• Data from major ISPs
• Non-existent in public
• Data from academia
• DAGMON traces at KAIST
• Long-term, sampled flow-level traces at POSTECH
• 4-month-worth NetFlow traces at CNU
• Others
• 3G video streaming service data
• 2-day packet-level traces from a home network

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Diverse Data Sets in Korea

• Data from major ISPs
• Non-existent in public
• Data from academia
• DAGMON traces at KAIST
• Long-term, sampled flow-level traces at POSTECH
• 4-month-worth NetFlow traces at CNU
• Others
• 2-day packet-level traces from a home network
• 3G video streaming service data

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2005.11.23 at KAIST
In Bits/Sec
No. of Pkts / sec
Others
Others
P2P
P2P
FTP
HTTP
FTP
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2004.12.9. at KAIST
In Bits/Sec
No. of Pkts / sec
Others
Others
P2P
P2P
HTTP
FTP
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REMOVE after chat with SY

• Previous slides upstream or downstream?
• According to JH Youn
• Upstream 70/85 (Bytes/Pkts) p2p
• Downstream Web and VOD more dominant that p2p.

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Home Networking in Korea

• Architecture
• Simple, tree-like topology
• To each home 100ME
• Internal links 1GE
• Outbound speed OC-3 or up
• Reality in new apt complexes
• Control home appliances thru the net
• washing machine, gas stove, lights,
  heater/airconditioner, door lock
• by PDAs at home or remotely by cellphones/web
  access
• Replace DSL/cable lines
• Will be "backbone" for home ubiquitous sensor
  network
• Need for remote monitoring
• Lack of resources

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2004.12.11. at a Home Network
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Video Streaming over 3G

• Goals of Monitoring
• To satisfy every user
• High revenue-generating customers
• More focus on per-user performance
• Challenges
• E2E performance segmented over cellular and wired
  networks
• No integrated monitoring solutions yet
• No good metric for overall/single-user performance

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Provisioning for Interactive Streaming

• Interactive Streaming
• Not a driving force behind b/w
• A candidate for growing revenue
• Examples
• VoIP gradually taking over PSTN traffic
• Remote video viewing at door by cell phone
• Online game traffic
• "Good" routing more important than bandwidth

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Routing in the Internet
Inter-domain policy-based routing
Intra-domain shortest path routing
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Issues in "Good" Routing

• Misbehaving routing protocols
• BGP misconfigurations
• Pathological behaviors
• Frequent changes
• Even under normal circumstances
• Transient behaviors
• Inter/intra-domain routing not well understood

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Scenario for a Transient Routing Loop In Normal
Operation
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When a link fails, R1 is the first to detect.
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R3 is updated before R2.
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Finally R2 is updated, and the loop is resolved.
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CDF of Routing Loop Duration in Time
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VoIP experimental setup Boutremans2002

• Traffic injected in the network
• 200 byte UDP packets
• every 5ms.
• Packets captured and timestamped at end-systems.
• Traceroute runs continuously during the
  experiment.

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Information Sources

• IS-IS BGP listener logs
• Router logs from both ends of failing links
• Controlled bi-directional VoIP traffic between
  Reston and ATL
• SNMP data

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Delays (1 sec timescale)
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When the two interfaces went down
6.6 seconds
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When three links came back up
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Approaches To Fix It

• Fine-tuning parameters
• Timer values Alattinoglu2002
• Modify Routing Protocols
• Suppress advertisement and perform local
  rerouting using a backwarding table Lee04
• Centralized path computation Feamster04,Rexford04
  

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Our Approach

• Key Idea
• Find disjoint overlay path and send duplicate
  packets
• Assumptions
• Sender and receiver both within an AS
• Bidirectional link weights
• Extra income for extra b/w consumption
• Pros and cons
• Advantages
• No modification to current infrastructure
• Selective use by only those that need it
• Disadvantages
• Extra b/w consumption

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Basic Ideas
candidate relay nodes!!!
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Resilient to Failures
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Future Work

• Answer questions raised about diverse data sets
• Find best places for relay nodes in Inter-domain

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BACKUP
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Summary Local Convergence
Experiment IS-IS Convergence Service Disruptions
2 links down 5.1 sec 6.6 sec
2 links up 17.6 sec 0 sec
3 links down 5.9 sec 8.0 sec
3 links up 17.5 sec 0.95 sec

• Convergence delay during failures hurts more
• After IS-IS converges, extra delay due to FIB
  update

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Causes and Open Questions

• Why only after 30 secs?
• spf-interval set to 30secs
• What caused the 1.745 secs disruption?
• Unknowsn in GSR architecture
• What is the right timescale to propagate good
  news?