1. Todd Deshane Ashwin Venkatraman McNair Program Clarkson University
Transmitting and Tracking Packets of Data Through The TCP and UDP Network Protocols
Todd Deshane
Ashwin Venkatraman
McNair Program
Clarkson University

2. Overview Transmission Control Protocol (TCP)
User Datagram Protocol (UDP)
Research questions and methodology
Data analysis and conclusions

3. Internet Protocols user X English user Y e-mail client SMTP
server
TCP/UDP server
TCP/UDP
TCP/UDP server
IP server IP
IP server
Peers exchange units meaningful to each end; communicate
Uses services of lower layer to avoid complexity
ethernet
driver/card
IEEE standard
ethernet
driver/card
electric signals
CS454 (Computer Communication) Clarkson University, Summer 2002

4. Transmission Control Protocol (TCP)
What is it?
A protocol for data exchange
Establishes a connection between two hosts (computers) on a network
Delivers data in order and retransmits lost data

5. Transmission Control Protocol (TCP)
Handshaking
Reliable data transfer
Flow Control
Congestion Control
Hi there
Hey there, I am ready for data
Here it is
I got it. Ready for more!

6. User Datagram Protocol (UDP)
What is it?
A protocol that allows for fast data transfer
Does not establish connection (connectionless)
Makes a “best effort” to transfer data
Not very reliable!

7. User Datagram Protocol (UDP)
No Handshaking!
No Reliable data transfer
No Flow Control
No Congestion Control
Sending data!
Sending data!
Sending data!

8. TCP vs. UDP Stream-oriented Good network citizen Reliable
Connection established
Good network citizen
Congestion control
Flow control
Reliable
Datagram-oriented
Connectionless
Blasts Away
No congestion control
No flow control
Best-effort

9. Research Questions TCP UDP How much do we pay to use TCP?
Elegant Protocol
Lots of nice features
Slower
UDP
Barebones Protocol
Lacks reliability
Faster
How much do we pay to use TCP?
How do we measure performance?
What causes the differences in performance?

10. Measuring Network Traffic
Basic terminology:
Network data represented in packets
Packet sizes represented in bytes
Things to measure:
Elapsed Time
Total data sent … Total received
Effective Throughput (data received/time)
Efficiency (Percent received)

11. Procedure Method Start Server Send data to Receiver Record Statistics
Transmitter (Client)
Receiver (Server)
Method
Start Server
Send data to Receiver
Record Statistics

12. PCATTCP Software Utility
Created by Printing Communications Associates, Inc. (PCAUSA)
Windows version of Test TCP (TTCP)
Bench-marking tool for TCP and UDP
Command-line based
Modified to:
Automate the testing process
Use handshakes between trials
Enhance UDP transfers

13. Different PCATTCP Trials
Same Switch (same lab)
Same Host (same computer)
Same LAN (inside Clarkson)
Note: LAN stands for “Local Area Network”
LAN to LAN (Clarkson to SUNY Potsdam)
LAN to Internet (Clarkson to a Roadrunner service)

14. Results
Same Switch
Same LAN

15. Results
LAN to LAN
LAN to Internet

16. Conclusion TCP in common environments UDP lacks flow control
Sometimes much slower (LAN to Roadrunner)
Sometimes slightly slower (same LAN)
UDP lacks flow control
Two hosts on the same switch
Faster transfer

17. Future Plans Use larger data sets (instead of 8 MB, 1 Gig)
Use our PCATTCP software on Wireless technology
Port our PCATTCP version from Windows to UNIX
Test across platforms

18. Acknowledgements Ronald E. McNair Scholars Program
Dr. Jeanna Matthews, Clarkson University
The Computer and Technology Services at SUNY Potsdam