1. Managing Online Services
Jennifer Rexford
Fall 2010 (TTh 1:30-2:50 in COS 302)
COS 561: Advanced Computer Networks

2. Challenging Services multiple servers, multiple locations 3G WiFi
A service running on multiple servers in multiple data centers, serving multiple users in different locations. Users may be multi-homed and mobile, and their link bandwidth may vary.
WiFi
mobile host

3. real-time video streams (e.g., IPTV)
Challenging Services
real-time video streams (e.g., IPTV)
multiple receivers,
dynamic join/leave
. . .

4. 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

5. 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?