This measurement point sits at the interconnection point of NASA Ames, Moffet Field, and the MAE-West interconnection of Metropolitan Fiber Systems. This link is now an OC12c PoS link deploying PPP encapsulation. Because of that, traces currently contain only portions of the TCP/IP header. Specifically, the TCP source and destination port and 32-bit sequence number are included in the trace, the 32-bit acknowledgement number and further fields are not. In the tsh format trace file all the fields not captured at the moment are set to zero. This limitation will be removed with an upgrade to the DAG3 capture card firmware in the near future.
As of the end of 2000, AIX traces account for about 50% of the data volume captured by all of the PMA network analysis infrastructure daily. This ceased around end of 2001.
Between January 2002 and September 22nd 2002 the two directions of the trace file were not tightly synchronized due to a hardware bug with the Dag3.5 cards. This has been fixed with an upgrade of the dag software package.
We intend to publish a longer trace (about 35 minutes) in the near future, which will allow for flow (TCP and UDP connection) studies.
S. Feldman. MAE-West Link Utilization Statistics
K C Claffy, Greg Miller, Kevin Thompson: The nature of the beast: recent traffic measurements fron an Internet backbone, Proceedings of INET 1998.
Sean McCreary, k claffy: Trends in Wide Area IP Traffic Patterns: A View from Ames Internet Exchange, TC Specialist Seminar on IP Traffic Modeling, Measurement and Management, September 2000.