PSC and Cisco Researchers Author Extended Statistics for Internet Protocol
Matt Matthis [front] and John Heffner
PITTSBURGH, October 24, 2007 — Researchers from PSC's Advanced Networking group in collaboration with Cisco Systems have proposed a new Internet standard to help diagnose and resolve network performance problems. The document - "TCP Extended Statistics MIB," by PSC researchers Matt Mathis and John Heffner and Rajiv Raghunarayan of Cisco - describes extended performance statistics for TCP (transmission control protocol), a core software protocol that underlies the majority of Internet applications.
With the performance statistics defined by this document, diagnostic tools can - in situations of poor network performance - directly ask TCP why it is slow and gather information on the nature of the problem.
"It takes the guesswork out of network debugging," says Mathis. "If a network-based application is performing poorly, TCP can determine if the bottleneck is in the sender, the receiver, or the network itself. If the bottleneck is in the network, TCP can provide specific information about its nature."
"This RFC reflects a great deal of creative thinking and high-level work by talented people at PSC, Cisco and elsewhere," said PSC director of networking Wendy Huntoon, who also directs operations for National LambdaRail. "It will have a long-lasting positive impact on the performance of the Internet." This new standard is an outgrowth of the Web100 project, a collaboration among PSC and others (the National Center for Atmospherics Research, the National Center for Supercomputing Applications, the National Science Foundation, and Cisco Systems) to better realize the potential for high-speed data transmission available in advanced networks: http://www.web100.org
The TCP Extended Statistics document was adopted by the Internet Engineering Task Force as a standards track RFC (Request for Comment). The IETF is the open international community of network designers, operators, vendors, and researchers that is responsible for the evolution and standardization of Internet Protocols.
The instruments defined in the TCP Extended Statistics MIB (management information base) have enabled the creation of a number of diagnostic tools. PSC's own "pathdiag" uses key properties measured on a short section of a network path to extrapolate the performance of the full path. Other tools that rely on these performance statistics include the Network Diagnostic Tester (NDT) and Microsoft's "tcpanalyzer" in the Windows Vista SDK.
The Pittsburgh Supercomputing Center is a joint effort of Carnegie Mellon University and the University of Pittsburgh together with Westinghouse Electric Company. Established in 1986, PSC is supported by several federal agencies, the Commonwealth of Pennsylvania and private industry, and is a partner in the National Science Foundation TeraGrid program.