1. Evaluation and Comparison of Real-time Network Latency Phillip Marlow KoolSpan Inc. TJHSST Computer Systems Lab

2. What is Network Latency?

3. How is Data Transported? Link Layer o General Packet Radio Service (GPRS) o Ethernet o Wifi Internet Layer o Internet Protocol (IP) Transport Layer o Transmission Control Protocol (TCP) o User Datagram Protocol (UDP) Application Layer o Security (KoolSpan TrustChip) o Message Packing

4. What Causes Network Latency? Collisions Ordering Encryption/Decryption Packing/Unpacking o Link o Internet o Transport o Application Speed of Light Routing

5. Why Does Network Latency Matter? User Experience Delays on voice data are especially noticeable o Excellent < 300 ms o Good < 600 ms o Poor < 900 ms o Unacceptable > 900 ms

6. How is Network Latency Meausred?

7. How is Network Latency Measured? SYN

8. How is Network Latency Measured? ACK

9. Link Layer

10. Transport Layer

11. Application Layer

12. Results GPRS is unfit for voice communication UDP is faster than TCP Security doesn't make a serious impact on overall latency

13. Suggestions for Future Research 3G Network Time of Day Network Load

14. Evaluation and Comparison of Real-time Network Latency Special Thanks To: Anthony Fascenda - KoolSpan Inc Randy Latimer - TJHSST Matthew Pearce - TJHSST