Much of the material here was published in August 2006 as GN2-06-135v2 (DS3.3.3): PERT Performance Guides.

In September 2007, we held a PERT Training workshop - you can view audio/video recordings from this event.

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Table of Contents (AutoToc)

• Performance basics: How to report a performance problem, user-perceived performance (responsiveness, throughput, reliability), Why latency is important, the "Wizard Gap"
• Network performance metrics: OWD, RTT (bandwidth*delay product and "Long Fat Networks" (LFNs)), delay varation (Jitter), loss, reordering, MTU/Path MTU
• Network protocols
  • Transmission Control Protocol (TCP) - terminology
    • Window-based transmission, performance enhancements - Large TCP windows, buffer auto-tuning, Window Scaling option
    • Flow control and congestion avoidance, high-speed TCP variants and land speed records, Selective acknowledgements (SACK)
  • User Datagram Protocol (UDP)
  • Real-time Transport Protocol (RTP)
  • Stream Control Transmission Protocol (SCTP)
• Application protocols
  • File transfer: FTP vs. HTTP, Secure Shell (SSH), BitTorrent
  • InteractiveApplications
    • Multimedia - Voice over IP (VoIP), Videoconferencing
    • Multiplayer games and other collaborative environments
  • Media Streaming
    • Digital Video Transport System (DVTS)
• PERT Tools
  • General-purpose tools
  • Measurement tools
    • Traceroute-like tools (Unix traceroute,tcptraceroute,LFT,mtr,tracepath,...)
    • Bandwidth measurement tools (pchar, iperf, bwctl, netperf, RUDE/CRUDE, ttcp, NDT, Thrulay)
      • Scripts
    • ActiveMeasurementTools: ping, fping, OWAMP
      • Active measurement infrastructures - (HADES, RIPE TTM, QoSMetrics)
    • Passive measurement tools
      • SNMP-based tools: MRTG, RRDTool, Cricket
      • Netflow-based tools
      • Packet tracing and analysis: tcpdump, Wireshark (Ethereal), libtrace, Netdude, jnettop, tcptrace
      • Host and Application Measurement Tools: NetLogger, Web100
  • NREN tools and statistics: GÉANT, SWITCH (CH), PSNC (PL), HEAnet (IE), ISTF (BG), FCCN (PT), IUCC (IL), HUNGARnet (HU), RENATER (FR)
  • Network emulation: netem, dummynet, NIST, hxbt
• End-system (host) tuning
  • Operating system independent: Bugs, Hardware
  • Operating system specific: BSD, Linux (InterfaceQueueLength), MacOS/X, Solaris, MS-Windows
  • Adapters and drivers: Large Send Offload (LSO), Interrupt Coalescence, Large Receive Offload (LRO), Checksum Offload, TCP Offload Engines (TOEs), large MTUs ("jumbo frames")
• Application Development
  • Avoiding "chatty" protocols
  • Performance-friendly I/O interfaces
• Network tuning
  • Active Queue Management (AQM), Random Early Detection (RED), Explicit Congestion Notification (ECN)
  • Differentiated Services - Premium IP; Integrated Services
  • Sizing buffers in the network
  • Network proxies or so-called WAN accelerators
  • Cisco (IOS-) specific
  • Support for large frames ("jumbo MTUs")
• Evil Middlebox
  • Window scaling problems
  • HTTP Proxy
• Specific Network Technologies:
  • Ethernet: Duplex modes and auto-negotiation, LAN Collisions, LAN Broadcast Domains, Flow Control
  • Wireless LAN (802.11)
  • Mobile IP04 Jul 2008
  • Switches^?: Head-of-Line blocking
  • Router Performance: Architectures, Hardware Limits
  • End System Performance

• PERT Case Histories
• PerformancePeople - VanJacobson, SallyFloyd...
• Related Efforts - Tools (NLANR, E2EPI) - Standardization (IETF: IPPM...)
• Glossary

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-- ChrisWelti - 01 Mar 2005
-- SimonLeinen - 15 Apr 2005 - 04 Jul 2008
-- UlrichSchmid - 21 Apr 2005 - 07 Jun 2005
-- AlexGall - 05 Sep 2007
-- Blazej Pietrzak - 05 Sep 2007