1. Subject: On the Performance of Optimization Proxies for Data Services in Mobile Networks dariusz.rozanski@szczesliwice.net

2. Agenda: The need and challenge of HTTP optimization UMTS: Live Network Experience HTTP Protocol Acceleration Optimization Potential for HSDPA Conclusion Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net

3. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Need of HTTP Optimization Bandwidth HTTP Download Time Need for improvement GPRS44 kbit/s1 min !! UMTS384kbit/s15s ! HSDPA1 Mbit/s7s ! Download Time of Test Page: 230kbyte, 50 Objects

4. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Need of HTTP Optimization => Round Trip Time

5. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Challenge of HTTP Optimization Price of web location unawareness: multiple downloads, even if all content is located at the same site.

6. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Challenge of HTTP Optimization HTTP acceleration: improve bandwidth utilisation at the wireless interface – Make it look like a single file download

7. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Challenge of HTTP Optimization Download time = T BW +T Rest Rest depends on RTT (propagation, access proc.) Bandwidth ramp up (TCP, Wireless Access) BandwidthRTT GPRS44 kbit/s> 0.5s UMTS384kbit/sc.a. 0.15 HSDPA> 1 Mbit/s< 0.1s Data Compression + HTTP acceleration

8. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net The Challenge of HTTP Optimization Protocol Optimization: Wireless TCP: Initial Window, RTTO… HTTP Improvements and Proprietary Protocols

9. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net HTTP Optimization for UMTS: Live network experience no optimisation optimisation: data volume compressed to 15% bulk download time same filesize Considerable Optimization potential for UMTS Benchmark for offered solutions

10. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net HTTP Protocol Acceleration HTTP1.0: one TCP connection per HTTP transfer

11. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net HTTP Protocol Acceleration One Connection per Request Persistent Connections: less TCP overhead…. …. But lower bandwidth utilisation in general => Optimum utilisation with pipelining. Not implemented as default.

12. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net HTTP Protocol Acceleration 1. Increase Number of Connections: Optimization below optimum, but no Client SW needed 2. Pipeline Requests Better results, but proprietary Client SW needed.

13. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net HTTP Optimization: Potential for HSDPA standard HTTP Increased number of connections pipelining bestcase More than 50% improvement possible!

14. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net Conclusion –Apart from bandwidth enhancement and data compression: there is additional optimization potential for HTTP acceleration for mobile networks due to high RTT. –Sorrowful analysis and benchmarking of the offered solutions needed. –Optimization potential for HSDPA: download time should be improved to more than 50%.

15. Subject: Performance of Optimization Proxies dariusz.rozanski@szczesliwice.net thank you

16. Personal details: Name: Surname: Company: Phone: E-mail: Dr.Stefan Rugel O2 Germany +49 89 24424766 Stefan.Rugel@o2.com dariusz.rozanski@szczesliwice.net