How Can You Have QoS When

1
How Can You Have QoS When

• Jennifer Rexford
• ATT Labs--Research

2
How Can You Have QoS When

• A typographical error by a network operator can
  bring down your service?
• Routing anomalies and slow convergence might
  (temporarily) discard your traffic?
• You dont know how to set the QoS parameters and
  estimate your bill?
• You cant tell who is to blame for the QoS
  violation you have experienced?

3
A single typo can bring down your network?

• Router configuration problems
• Non-standard assembly language programming
• Configuring individual routers not a network
• Complexity in network protocols and mechanisms
• lead to performance problems
• Human error responsible for half of outages
• Security holes, resource inefficiency
• Delay and cost in configuring and troubleshooting
• and some research challenges
• Models of protocol configuration state
• Codifying of best common practices
• Tools for error checking and data mining
• Systems for automated configuration

4
The routing system discards your packets?

• Routing problems
• Transient instability during routing convergence
• Blackholes, route hijacking, policy oscillation,
• Congestion due to sub-optimal routing
  configuration
• lead to performance problems
• Packets dropped, discarded, or out-of-order
• Forwarding loops consuming extra bandwidth
• and some research challenges
• Faster data-plane convergence
• Detection and diagnosis of anomalies
• Checking of configuration errors and policy
  conflicts
• Better traffic engineering and capacity planning

5
Customers dont know what QoS params to select?

• QoS specification problems
• Dont know the traffic mix by 5-tuple
• Cant accurately map the 5-tuple to applications
• Cant predict how much their bill will be
• leads to slow QoS adoption
• Customers want QoS but cant specify it
• Customers want QoS but are wary of their bill
• and some research challenges
• Traffic measurement and characterization
• Digging below the 5-tuple in the IP/TCP header
• Mapping traffic classes into QoS classes

6
Customers dont know who is to blame?

• Finger-pointing problem
• Hard to detect QoS violations
• Even harder to diagnose them
• Even harder to ascribe blame
• leads to low end-to-end QoS adoption
• SLAs based just on basic availability
• SLAs only for on net traffic in one domain
• and some research challenges
• Measurements for the finger-pointing problem
• Techniques for outsourcing the finger-pointing to
  a third-party or the provider

7
Conclusion

• We need to solve these problems!