Efficient Content Distribution on
Internet
Who pays for showing a Web
page to a user?
• Receiving side
– Users pay to small ISPs, who pay to big ISPs,
who pay to even bigger ISPs;
– Concerns: reduce traffic / better response time
• Sending side
– Web sites pay to ISP, or aggregators of ISPs
(example: broadcast, akamai);
– Concerns? It depends...
A Simplistic View: Two Kinds of
Web Sites
• Portals: really want to be seen and want to
be seen with high quality
• Libraries: be available
Who should pay for showing a
Web page to the user?
1. Library pages: the user
2. Portal pages: the Web site
Many ISPs so far are focusing on 1 (the users,
cutting down traffic), and ignoring 2 (the
content providers, QoS)
– the ignorance creates a vacuum that lets
akamai.com flourish
What should be done?
• A mechanism that links ISPs and Portals
– Addressing the logistical difficulties:
• One ISP charging many portals for content delivery;
• One portals getting certain assurance of QoS from
many ISPs
• Trust between the parties
• The mechanism should also be efficient
– Caching, Replication, Routing, Differentiality
Peregrine Net Inc.
• To ISP:
– Caching proxy
– Caching proxy plus services --- 1-6 months
– Content distribution box
• To Portals:
– Web acceleration proxy
– ISP-coordinated QoS and load distribution --- 1-6
months
– URL rewrite for content distribution
The Proxy Products
• Runs on Linux, FreeBSD, Solaris, NT and
other standard OS
• Scales from < 10Mb/s to over 4Gb/s
• Tiered pricing:
–
–
–
–
–
<10Mb/s: free
10Mb/s - 30Mb/s: $2K-4K per copy
30Mb/s - 60Mb/s: $10K per copy or appliance
60Mb/s - 155Mb/s: more expensive
155Mb/s and up: clustering, even more expensive
Service 1: Premium Content
Management
• Portals pay ISP for each object delivered
from cache
• * Optimal cache management balancing
needs of users and thost of portals
• * Efficient hit reporting to portals
• Establishing trust:
– Third-party inspection of software
– statistical analysis of hit reports
• Estimated time: 2 months
Service 2: Active Cache Proxy
• Caching objects instead of datagrams
– Web servers provide a piece of code (cache
applet) that is associated with an object
– The object and code are cached at the proxy;
upon cache hit, the code is executed to generate
responses
• Example: user-customized Web pages
• Benefit: Scale the Web server!
• Estimated time: 3-6 months
Service 3: Content Distribution
• Routing methods:
– At Web server: rewrite URLs for image objects
• what Sandpiper and Akamai are doing
– At proxy: redirect URLs to content distribution
box, or mark objects as permanently cached
• * Optimal load balancing
– Constant server + network load-monitoring
• * Efficient content authentication
• Estimated time: 3-6 months
Service 4: Rent-A-Server
• Rent when needed:
– Web accelerator monitoring the load
– If load exceeds limit, redirect or route requests
to “rental” servers
• Rental servers capable of handling dynamic
contents via process migration technology
• * Optimal server selection algorithm
• Estimated time: 6 months
How are we different from
everyone else?
• We do what everyone else does
• We return part of the profits to ISPs, who
carry the bits
But, in addition
• Everyone uses our proxies
• Proxies control the routing
• Proxies can do arbitrary transformation on
the URLs
Additional Service: Mining the
Log
• Web server performance data
• User auto-rating of search results
– Which item really answered the user’s
question? Guess it from user’s surfing
– Technique: build the user’s surfing graph with
the search result as root
• User-profiling and feedback to Ad servers
Looking Forward: Efficient
Video Content Distribution
• Caching proxy capable of handling video
streams
• A hierarchy of caching proxies for video
distribution
– * Efficient “Prefix-Caching” algorithm
– * Object popularity probing, and optional
Satellite distribution for very popular objects
Steps to get there
• 1. proxy product and sales
– Current beta testers: Siemens AG, Union Bank of
Swiss, NetOne (Japan), a medium-size ISP in UK,
JANET in UK
• 2. Premium content management, active
caching proxy, content distribution service
• 3. Rent-A-Server
After sufficient proxy deployment: log-mining
and video distribution