decides which methods that are possible. Data
reduction is especially crucial for passive mea-
surements (packet traces and flow records) that
generate huge amounts of data. Large amounts
of measurement data should be transported with-
out any disturbance of the network operation.
As differentiation is introduced in IP networks,
the benefits and motivation to collect and anal-
yse measurement data will increase. The service
level agreements between various actors must
state precisely what is being measured and how
the measurements are performed. Since in a dif-
ferentiated services network the traffic is catego-
rized into flow types or priority classes, the per-
formance within each category must be mea-
sured. This can easily be achieved both by active
and passive measurements. However, it will be
more important to measure the performance of
real-time and premium services with strict per-
formance requirements than the best-effort ser-
vices. Thus, measurements of various granular-
ity may be needed for different service qualities.
References
[Brownlee] Brownlee, N. NeTraMet.(2001,
August 13) [online] – URL: http://www.auck-
land.ac.nz/net/NeTraMet/
[Calvert97] Calvert, K L, Doar, M B, Zegura,
E W. 1997. Modeling Internet Topology. IEEE
Communication Magazine,35 (6), 160–163.
[Careces91] Cáceres, R et al. 1991. Characteris-
tics of Wide-Area TCP/IP Conversations. In:
Proceedings of ACM SIGCOMM’91,101–112.
[Cflowd] McRobb, D W. cflowd design.(2001,
August 13) [online] – URL: http://www.caida.
org/tools/mea-surement/cflowd/design/
design.html
[Claffy95] Claffy, K C, Braun, H-W, Polyzos,
G C. A Parametrizable methodology for Internet
traffic flow profiling.(2001, August 13) [online]
- URL: http://www.caida.org/outreach/papers/
pmi.html
[Claffy97] Apisdorf, J et al. 1997. OC3MON:
Flexible, Affordable, High-Performance Statis-
tics Collection. In: Proceedings of INET`97.
(2001, August 13) [online] – URL: http://www.
isoc.org/isoc/whatis/confer-ences/inet/97/
proceedings/longtoc.HTM. Kuala Lumpur,
Malaysia.
[Claffy98] Claffy, K C, Miller, G, Thompson, K.
- The nature of the beast: recent traffic mea-
surements from an Internet backbone. In: Pro-
ceedings of INET’98.(2001, August 13) [online]
- URL: http://www.caida.org/outreach/papers/
Inet98/
[Coral] Cooperative Association for Internet
Data Analysis (CAIDA), CoralReef.(2001,
August 13) [online] – URL: http://www.
caida.org/tools/measurement/coralreef/[Fraleigh] Fraleigh, C et al. 2001. Design and
deployment of a passive monitoring infrastruc-
ture. In: Proceedings of PAM2001,Amsterdam,
The Netherlands.[Graham] Graham, I D et al. 1998. Nonintrusive
and Accurate Measurements of Unidirectional
Delay and Delay Variation on the Internet. In:
Proceedings of INET’98.(2001, August 13)
[online] – URL: http://www.comms.uab.es/
inet99/inet98/longtoc.htm[Heegaard] Heegaard, P, Viken B Å. 2001. A
distributed test environment for IP performance
evaluation. Telektronikk, 97 (2/3), 245–268.
(This issue.)[I.380] ITU. 1998. Internet Protocol Data Com-
munication Service – IP Packet Transfer and
Availability Performance Parameters.Geneva.
(Draft ITU-T I.380.)[Lindh] Lindh, T. 2000. An architecture for
embedded monitoring of QoS parameters in IP
based virtual private networks. In: Proceedings
of the 15th Nordic Teletraffic Seminar,Lund,
Sweden, 115–124.[MOAT] National Laboratory for Applied Net-
work Research, Measurement and Operations
Analysis Team (NLANR/MOAT).(2001, August
13) [online] – URL: http://moat.nlanr.net/[McGregor] McGregor, A, Braun, H-W, Brown,
J. 2000. The NLANR Network Analysis Infras-
tructure. IEEE Communications Magazine, 38
(5), 122–128.[NAI] NLANR/MOAT Network Analysis Infras-
tructure (NAI).(2001, August 13) [online] –
URL: http://moat.nlanr.net/NAI/[NIMI] Paxson et al. 1998. An Architecture for
Large-Scale Internet Measurement. IEEE Com-
munications,36 (8), 48–54.[NetFlow99] Cisco Systems, Inc. NetFlow ser-
vices and Applications. White paper.(2001,
August 13) [online] – URL: http://www.cisco.
com/warp/public/cc/pd/iosw/ioft/neflct/tech/
napps_wp.pdf[ocxmon] NLANR/MOAT Passive Measurement
and Analysis.(2001, August 13) [online] – URL:
http://moat.nlanr.net/PMA/