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Network Working Group S. ParkerRequest for Comments: 2398 C. SchmechelFYI: 33 Sun Microsystems, Inc.Category: Informational August 1998 Some Testing Tools for TCP ImplementorsStatus of this Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved.1. Introduction Available tools for testing TCP implementations are catalogued by this memo. Hopefully disseminating this information will encourage those responsible for building and maintaining TCP to make the best use of available tests. The type of testing the tool provides, the type of tests it is capable of doing, and its availability is enumerated. This document lists only tools which can evaluate one or more TCP implementations, or which can privde some specific results which describe or evaluate the TCP being tested. A number of these tools produce time-sequence plots, see Tim Shepard's thesis [She91] for a general discussion of these plots. Each tools is defined as follows: Name The name associated with the testing tool. Category One or more categories of tests which the tools are capable of providing. Categories used are: functional correctness, performance, stress. Functional correctness tests how stringent a TCP implementation is to the RFC specifications. Performance tests howParker & Schmechel Informational [Page 1] RFC 2398 Some Testing Tools for TCP Implementors August 1998 quickly a TCP implementation can send and receive data, etc. Stress tests how a TCP implementation is effected under high load conditions. Description A description of the tools construction, and the implementation methodology of the tests. Automation What steps are required to complete the test? What human intervention is required? Availability How do you retrieve this tool and get more information about it? Required Environment Compilers, OS version, etc. required to build and/or run the associated tool. References A list of publications relating to the tool, if any.2. Tools2.1. Dbs Author Yukio Murayama Category Performance / Stress Description Dbs is a tool which allows multiple data transfers to be coordinated, and the resulting TCP behavior to be reviewed. Results are presented as ASCII log files. Automation Command of execution is driven by a script file.Parker & Schmechel Informational [Page 2] RFC 2398 Some Testing Tools for TCP Implementors August 1998 Availability See http://www.ai3.net/products/dbs for details of precise OS versions supported, and for download of the source code. Current implementation supports BSDI BSD/OS, Linux, mkLinux, SunOS, IRIX, Ultrix, NEWS OS, HP-UX. Other environments are likely easy to add. Required Environment C language compiler, UNIX-style socket API support.2.2. Dummynet Author Luigi Rizzo Category Functional Correctness / Performance Description Dummynet is a tool which simulates the presence of finite size queues, bandwidth limitations, and communication delays. Dummynet inserts between two layers of the protocol stack (in the current implementation between TCP and IP), simulating the above effects in an operational system. This way experiments can be done using real protocol implementations and real applications, even running on the same host (dummynet also intercepts communications on the loopback interface). Reconfiguration of dummynet parameters (delay, queue size, bandwidth) can be done on the fly by using a sysctl call. The overhead of dummynet is extremely low. Automation Requires merging diff files with kernel source code. Command-line driven through the sysctl command to modify kernel variables. Availability See http://www.iet.unipi.it/~luigi/research.html or e-mail Luigi Rizzo (l.rizzo@iet.unipi.it). Source code is available for FreeBSD 2.1 and FreeBSD 2.2 (easily adaptable to other BSD-derived systems). Required Environment C language compiler, BSD-derived system, kernel source code. References [Riz97]Parker & Schmechel Informational [Page 3] RFC 2398 Some Testing Tools for TCP Implementors August 19982.3. Netperf Author Rick Jones Category Performance Description Single connection bandwidth or latency tests for TCP, UDP, and DLPI. Includes provisions for CPU utilization measurement. Automation Requires compilation (K&R C sufficient for all but-DHISTOGRAM, may require ANSI C in the future) if starting from source. Execution as child of inetd requires editing of /etc/services and /etc/inetd.conf. Scripts are provided for a quick look (snapshot_script), bulk throughput of TCP and UDP, and latency for TCP and UDP. It is command-line driven. Availability See http://www.cup.hp.com/netperf/NetperfPage.html or e-mail Rick Jones (raj@cup.hp.com). Binaries are available here for HP/UX Irix, Solaris, and Win32. Required Environment C language compiler, POSIX.1, sockets.2.4. NIST Net Author Mark Carson Category Functional Correctness / Performance Description NIST Net is a network emulator. The tool is packaged as a Linux kernel patch, a kernel module, a set of programming APIs, and command-line and X-based user interfaces. NIST Net works by turning the system into a "selectively bad" router - incoming packets may be delayed, dropped, duplicated, bandwidth- constrained, etc. Packet delays may be fixed or randomly distributed, with loadable probability distributions. Packet loss may be uniformly distributed (constant loss probability) or congestion-dependent (probability of loss increases with packet queue lengths). Explicit congestion notifications may optionally be sentParker & Schmechel Informational [Page 4] RFC 2398 Some Testing Tools for TCP Implementors August 1998 in place of congestion-dependent loss. Automation To control the operation of the emulator, there is an interactive user interface, a non-interactive command-line interface, and a set of APIs. Any or all of these may be used in concert. The interactive interface is suitable for simple, spur-of-the-moment testing, while the command-line or APIs may be used to create scripted, non-interactive tests. Availability NIST Net is available for public download from the NIST Net web site, http://www.antd.nist.gov/itg/nistnet/. The web site also has installation instructions and documentation. Required Environment NIST Net requires a Linux installtion, with kernel version 2.0.27 - 2.0.33. A kernel source tree and build tools are required to build and install the NIST Net components. Building the X interface requires a version of XFree86 (Current Version is 3.3.2). An Athena-replacement widget set such as neXtaw (http://www.inf.ufrgs.br/~kojima/nextaw/) is also desirable for an improved user interface. NIST Net should run on any i386-compatible machine capable of running Linux, with one or more interfaces.2.5. Orchestra Author Scott Dawson, Farnam Jahanian, and Todd Mitton Category Functional Correctness / Performance Description This tool is a library which provides the user with an ability to build a protocol layer capable of performing fault injection on protocols. Several fault injection layers have been built using this library, one of which has been used to test different vendor implementations of TCP. This is accomplished by probing the vendor implementation from one machine containing a protocol stack that has been instrumented with Orchestra. A connection is opened from the vendor TCP implementation to the machine which has been instrumented. Faults may then be injected at the Orchestra side of the connection and the vendor TCP's response may be monitored. The most recent version of Orchestra runs inside the X-kernel protocol stack on the OSF MK operating system.Parker & Schmechel Informational [Page 5] RFC 2398 Some Testing Tools for TCP Implementors August 1998 When using Orchestra to test a protocol, the fault injection layer is placed below the target protocol in the protocol stack. This can either be done on one machine on the network, if protocol stacks on the other machines cannot be modified (as in the case of testing TCP), or can be done on all machines on the network (as in the case of testing a protocol under development). Once the fault injection layer is in the protocol stack, all messages sent by and destined for the target protocol pass through it on their way to/from the network. The Orchestra fault injection layer can manipulate these messages. In particular, it can drop, delay, re-order, duplicate, or modify messages. It can also introduce new messages into the system if desired. The actions of the Orchestra fault injection layer on each message are determined by a script, written in Tcl. This script is interpreted by the fault injection layer when the message enters the layer. The script has access to the header information about the message, and can make decisions based on header values. It can also keep information about previous messages, counters, or any other data which the script writer deems useful. Users of Orchestra may also define their own actions to be taken on messages, written in C, that may be called from the fault injection scripts. Automation Scripts can be specified either using a graphical user interface which generates Tcl, or by writing Tcl directly. At this time, post-analysis of the results of the test must also be performed by the user. Essentially this consists of looking at a packet trace that Orchestra generates for (in)correct behavior. Must compile and link fault generated layer with the protocol stack. Availability See http://www.eecs.umich.edu/RTCL/projects/orchestra/ or e-mail Scott Dawson (sdawson@eecs.umich.edu). Required Environment OSF MK operating system, or X-kernel like network architecture, or adapted to network stack. References [DJ94], [DJM96a], [DJM96b]Parker & Schmechel Informational [Page 6] RFC 2398 Some Testing Tools for TCP Implementors August 19982.6. Packet Shell Author Steve Parker and Chris Schmechel Category Functional Correctness / Performance Description An extensible Tcl/Tk based software toolset for protocol development and testing. Tcl (Tool Command Language) is an embeddable scripting language and Tk is a graphical user interface toolkit based on Tcl. The Packet Shell creates Tcl commands that allow you to create, modify, send, and receive packets on networks. The operations for each protocol are supplied by a dynamic linked library called a protocol library. These libraries are silently linked in from a special directory when the Packet Shell begins execution. The current protocol libraries are: IP, IPv6, IPv6 extensions, ICMP, ICMPv6, Ethernet layer, data layer, file layer (snoop and tcpdump support), socket layer, TCP, TLI. It includes harness, which is a Tk based graphical user interface for creating test scripts within the Packet Shell. It includes tests for no initial slow start, and retain out of sequence data as TCP test cases mentioned in [PADHV98]. It includes tcpgraph, which is used with a snoop or tcpdump capture file to produce a TCP time-sequence plot using xplot. Automation Command-line driven through Tcl commands, or graphical user interface models are available through the harness format. Availability See http://playground.sun.com/psh/ or e-mail owner-packet- shell@sunroof.eng.sun.com. Required Environment Solaris 2.4 or higher. Porting required for other operating systems.Parker & Schmechel Informational [Page 7] RFC 2398 Some Testing Tools for TCP Implementors August 19982.7. Tcpanaly Author Vern Paxson Category Functional Correctness / Performance Description This is a tool for automatically analyzing a TCP implementation's behavior by inspecting packet traces of the TCP's activity. It does so through packet filter traces produced by tcpdump. It has coded within it knowledge of a large number of TCP implementations. Using this, it can determine whether a given trace appears consistent with a given implementation, and, if so, exactly why the TCP chose to transmit each packet at the time it did. If a trace is found inconsistent with a TCP, tcpanaly either diagnoses a likely measurement error present in the trace, or indicates exactly whether the activity in the trace deviates from that of the TCP, which can greatly aid in determining how the traced implementation behaves. Tcpanaly's category is somewhat difficult to classify, since it attempts to profile the behavior of an implementation, rather than to explicitly test specific correctness or performance issues. However,⌨️ 快捷键说明
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