Network Working Group                          Internet Activities Board
Request for Comments: 1262                   Vinton G. Cerf/CNRI, Editor
                                                            October 1991

             Guidelines for Internet Measurement Activities

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard.  Distribution of this memo is


   Measurement of the Internet is critical for future development,
   evolution and deployment planning.  Internet-wide activities have the
   potential to interfere with normal operation and must be planned with
   care and made widely known beforehand.  This document offers guidance
   to researchers planning Internet measurements.

   This RFC represents IAB guidance for researchers considering
   measurement experiments on the Internet.  This RFC does not represent
   a standard for the Internet but the Internet Activities Board
   strongly urges that Internet users follow the guidelines out of
   courtesy and professional consideration for the Internet community.


   The Internet has undergone dramatic growth in connectivity, use, and
   quality of service over the past several years.  As this growth
   continues and the Internet is used for increasingly diverse and
   demanding purposes, it is vital to collect data about a range of
   functions, from low-level packet switching services to considerations
   for the networking expectations of individual applications.  Such
   data is vital to research and engineering planning activities, as
   well as to ensure the continued development of the operational
   infrastructure.  Yet, it is also important that data collection
   activities do not interfere with the operational viability and
   stability of the network, and do not violate considerations regarding
   privacy, security, and acceptable use policies of the network.  In
   this light, the Internet Activities Board offers the following basic
   guidelines for network measurement activities.

   In general, any data collection activity should be undertaken with
   professional consideration of its impact on the services and users of
   the network, and activities should be planned to achieve operational

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RFC 1262                 Measurement Guidelines             October 1991

   or research goals with minimal impact.  In some cases, data may be
   collected continuously, for example to measure packet counts or the
   distribution of use of specific applications.  In other cases, the
   planned investigations will be too demanding to be undertaken
   continuously, because of the intensity of effort required by the
   researcher or the traffic load on the underlying network
   infrastructure.  Any data collection activity should be designed with
   careful consideration of this type of issue, and should be tested
   thoroughly before being deployed on the Internet.  Any individual
   initiating a network measurement activity should alert the relevant
   service providers using mechanisms such as bulletin boards, mailing
   lists and individual mail communications.

   Furthermore, the data being collected must not be gathered using
   break-ins to network systems or other illegal or unethical
   techniques.  If a measurement activity might be construed as a
   possible security intrusion, the researcher should make it easy for a
   system administrator at a remote site to determine that the activity
   is not a break in attempt, by informing the CERT, making information
   about the study easily available by anonymous FTP or other means

   More specifically, an individual attempting a network measurement
   activity should ensure that the following conditions are met:

     1) the data collected will not violate privacy, security, or
        acceptable use concerns,

     2) if the aggregated data has a potential for privacy intrusions,
        the researcher must protect privacy, for example by limiting
        published statistics in such a fashion that individual users or
        institutions are not identified,

     3) if the data collection activity may be construed to be a
        security violation, the researchers are strongly advised to
        inform the CERT in advance, and, if applicable, request some

     4) the data collection does not unduly load or otherwise interfere
        with the network or attached machines, in particular, if at all
        feasible, non-invasive measurement, like passive monitoring,
        should be considered as the first choice,

     5) if there is an operational impact, the service providers must be

     6) the study goals, methodology, and plans are widely available, in
        a fashion that requires minimal effort to locate and retrieve,

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RFC 1262                 Measurement Guidelines             October 1991


     7) if the activity would impose undue burden on a remote machine or
        network, the measurements should not be performed without prior
        explicit permission.


     [1] Internet Activities Board, "Ethics and the Internet", RFC-1087,
         January 1989.

     [2] Holbrook, P., and J. Reynolds, (Eds.), "Site Security
         Handbook", RFC-1244, FYI-8, CICnet and USC Information Sciences
         Institute, July 1991.

     [3] Computer Emergency Response Team/Coordination Center (CERT/CC),
         Software Engineering Institute, Carnegie Mellon University,
         Pittsburgh, PA 15213-3890, Internet E-mail:, Telephone: 412-268-7090 24-hour hotline.

Security Considerations

   The body of this memo does discuss security issues related to network
   measurement, particularly the potential confusion of benign
   measurement with hostile security attacks.

Author's Address

   Vinton G. Cerf
   Chair of the IAB
   Corporation for National Research Initiatives
   1895 Preston White Drive, Suite 100
   Reston, VA 22091



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