Transcript Online Services

Managing Online Services
Jennifer Rexford
Fall 2010 (TTh 1:30-2:50 in COS 302)
COS 561: Advanced Computer Networks
http://www.cs.princeton.edu/courses/archive/fall10/cos561/
Challenging Services
multiple servers,
multiple locations
3G
WiFi
mobile host
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Challenging Services
real-time video
streams (e.g., IPTV)
multiple receivers,
dynamic join/leave
...
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Today’s Internet Architecture
• Best-effort, unicast packet-delivery service
– Though some services need real-time performance
– Though some services need multicast or anycast
• IP addresses correspond to a fixed machine
– Location-dependent
– Addresses a single point-of-attachment
– Visible to applications
• Domain names
– Variable length
– Name a machine, not a service
– Early binding of name to IP address
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Questions
• Directing client requests to server replicas
• Seamless client and/or server mobility
• Directing the same content to many clients
• Real-time applications
• Adapting services to client’s geographic location
How to address these issues today?
How to change the Internet architecture to make them easier?
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