The Akamai Network: A platform for high-performance Internet application

1. The Akamai Network: A platform for high-performance Internet application Erick Nygren, Jennifer Sun, Akamai Technologies Vasileios Pappas, Akamai Technologies and University of Massachusetts ACM SIGOPS 2010 Speaker : Conque, Kim cqkim@mmlab.snu.ac.kr

2. Outline • Introduction • Overview of the Akamai platform • Akamai HD network • Conclusion

3. Introduction • Possible risks of the current Internet for businesses • Reliability • Designed as best effort network, the Internet provides no guarantees on end-to-end reliability • Single one-hour outage can cause significant damage to brand reputation of e-commerce companies • Performance • Inherent limitation in the Internet makes difficult to achieve desired levels of performance for accessing the commercial sites • e.g. application adoption and site conversion rates • Large-scale distributed computing platform is needed • First-pioneered one is the Akamai network

4. Problem about performance • For supporting web content and streaming media, current network has a limitation • The distance between server and end user becomes a bottleneck for video throughput • [Fig] Effect of distance on throughput and download time

5. Akamai network • One of the world's largest distributed computing platforms • Feature of the Akamai • Delivery network for evolving the business network • First pioneering the concept of Content Delievery Network • Replicating and delivering content and applications at the edge of the Internet, close to the end users • Virtual network for the existing Internet • Working over the existing Internet as-is

6. Benefits of Akamai • Speed up remote user application performance • Reduce server load • Improve application delivery reliability • Reduce bandwidth usage at main server datacenter • Improve application security [Fig] Global performance with and without Akamai *borrowed from ADCAP Network system`s site

7. Outline • Introduction • Overview of the Akamai network • Akamai HD network • Conclusion

8. Backup Slides The Akamai EdgePlatform: 105,000+ Servers 1900+ POPs 950+Networks 750+ Cities 78+ Countries • Resulting in traffic of: • 5.4 petabytes/ day • 790+ billion hits / day • 436+ million unique clients IPs / day • POP : Point of presence

9. Anatomy of a delivery network www.naver.com/image.jpg ? End Users Transport Sys. Pull-based caching Contents ak.naver.com/image.jpg Mapping Sys. Data collection & analysis

10. Akamai`s Mapping system • Main parts of the mapping system • Scoring system • Creating current, topological map capturing the state of connectivity across the entire Internet • Using equivalent classes of IP address and historic and real-time data like pings, traceroutes, and etc. • Real-time mapping • Creating actual maps used by the Akamai platform to direct end users based on the scored data

11. Outline • Introduction • Overview of the Akamai platform • Akamai HD network • Conclusion

12. Delivery network for high performance • Video-grade scalability • Current network including datacenter and peering points is no longer sufficient to support • Solution, ‘IP-layer multicasting’ is no more practical in reality • Streaming performance • Multi dimensional and complex streaming performance need measurements for efficiency • Stream availability, startup time, highest bitrate and effective bandwidth are a good metrics for optimizing the network • Monitoring infrastructure built by Akamai are measuring the metrics above

13. Process of streaming CDN Encoder Entrypoint Subscribe Publish Original File Set reflector Set reflector Set reflector Publish Subscribe Edge reflector Edge Server Edge Server Edge reflector Edge reflector Edge Server Streaming Server Streaming Server Streaming Server Multicast Communication Publish Subscribe Mapping to end users

14. Techs. for quality of streaming • Packet loss recovery • Collecting traces of packet flows that were at least 1 h long, and spanning a lots of packets • By using parity bits for single or multiple streams or using plain retransmission, they can reduce packets` loss rate • Adaptive multipath transmission • Replicating packets originating from a particular entrypoint and sending across multiple set reflectors to a single edge region • Modifying the streaming server to provide stream quality information to the edge reflectors

15. Techs. for quality of streaming • Prebursting • Delivering a stream to a server at a higher rate than the encoded rate for the first few seconds of the streaming session`s life • Advantages • Reuse the retransmit buffers as the prebursting buffers • Reduce buffering time x 9

16. Outline • Introduction • Overview of the Akamai platform • Akamai HD network • Conclusion

17. Conclusion • Akamai network uses the cache functionality of edge node for improving the service of B2B networks • Akamai has been providing their own technics for improving the end-to-end network performance, and now especially on the HD network for live streaming • Packet loss recovery, multipath transmission, and prebursting