Read the instructions to get
the latest distribution of ANCLES and CLASS
from the download page
Introduction
CLASS is a simulator for ATM networks that was developed by
the Telecommunication Networks Group of
Politecnico di Torino in co-operation with
CSELT (Centro Studi E
Laboratori Telecomunicazioni) under the research contract
``Valutazione di Traffico nell'Interconnessione MAN/ATM''
(Traffic Evaluation in MAN/ATM Interconnection) and with the Technical
University of Budapest, Hungary.
CSELT owns the software and currently holds its
distribution rights.
CLASS stands for Cell Level ATM Services Simulator (formerly
ConnectionLess ATM Services Simulator) and,
as the old name goes, it is devoted to the simulation of connectionless
traffic, basically
the services offered by B-ISDN (Broadband Integrated Services Digital
Network), on networks based on the ATM technology.
Simulations performed by CLASS are at the cell level,
taking into account
routing and switching functions, the allocation of the bandwidth to
different connections, the possible presence in the network
of special nodes devoted to the management of connectionless traffic
and many other functions that may influence the performance on the network
as a whole.
Using CLASS
CLASS offers the opportunity of defining arbitrary topologies with
a great
freedom on the number of nodes within the network, the number of ports
connected to each node, the characteristic of the traffic and so on. The
topological description of the network, is done through a specialized
formal grammar that allows the easy check of the topology definition
Results obtained during the simulation are all written onto ASCII
files and can be easily postprocessed with standard data analysis tools.
Results comprise several
statistics about messages and cells generated during the
simulation, and are referred both to the whole
network and to each single link or traffic relation.
CLASS Features
The main features of
CLASS are:
Several types of traffic sources (among which a DQDB-like and a TCP source)
A GCRA-derived shaping function can be applied to the traffic produced by
each source
A GCRA-based policing function at the node input interface
(both tagging and discarding cells)
A dedicated language is used to describe the topology and the parameters of
the network to be simulated
A fixed priority or a Fair Queueing algorithm can be
implemented at the output interface of the nodes
Implementation of the ATM Forum ABR transfer capability
Several ABR traffic control schemes (RRM, ER) implemented in the nodes
Integration with ANCLES, the
companion Call Level simulator
A special CLASS version has been developed to manage Wireless ATM
Networks and
the analysis of different handover strategies.
Portability
CLASS is completely written in ANSI C language and works without
modifications on several platforms. Currently it has been tested under OpenVMS
(VAX and AXP), Linux,
HP-UX, Ultrix and MS-DOS (using DJGPP, the MS-DOS version of
the GNU C compiler). Generally, it should compile on every system supporting
an ANSI C compiler (prototypes are heavily used). It also requires
the presence of YACC and FLEX.
No graphical interface has been so far developed.
The current version of CLASS is
6.20h. This version is currently
available to academic parties for research purposes.
References
References to CLASS-related papers:
M. Ajmone Marsan, R. Lo Cigno, M. Munafò, A. Tonietti,
``Simulation of ATM Computer Networks with CLASS'',
7th International Conference on Modelling Techniques and Tools for Computer
Performance Evaluation, Vienna, Austria, May 1994
M. Ajmone Marsan, R. Lo Cigno, M. Munafò, A. Tonietti,
``A Source Model for Connectionless Traffic in B-ISDN'',
5th IFIP Conference on High Performance Networking, Grenoble, France,
June 1994
M. Ajmone Marsan, T.V. Do, L. Jereb, R. Lo Cigno, R. Pasquali,
A. Tonietti, ``Simulation of Traffic Shaping Algorithms in ATM
Networks'',
Second Workshop on Performance Modeling and Evaluation of ATM
Networks, Bradford UK, July 1994
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``TCP over ATM: Some Simulation Results'', Open Workshop on High
Speed Networks, Brest, France, September 1994
M. Ajmone Marsan, C. Casetti, M. Munafò, J. Valdes,
``Fair Queueing in ATM Networks: A Simulation Study'',
Third Workshop on Performance Modeling and Evaluation of ATM
Networks, Ilkley UK, July 1995
R. Lo Cigno, M. Munafò,
``RC - A Flexible Language for the Specification of ATM Networks
Simulation Experiments'',
Third Workshop on Performance Modeling and Evaluation of ATM
Networks, Ilkley UK, July 1995
G. Wolfner, T.V. Do, L. Jereb, K. Umann,
``Simulation Results on Scheduling Shaped Cell Streams'',
Third Workshop on Performance Modeling and Evaluation of ATM
Networks, Ilkley UK, July 1995
T.V. Do, L. Jereb, K. Umann, G. Wolfner,
``Simulation Comparison of Link Scheduling Algorithms: Impacts on
Cell Delay Variation'',
Third Workshop on Performance Modeling and Evaluation of ATM
Networks, Ilkley UK, July 1995
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``Shaping and Policing in ATM Networks'',
Journal on Communications, Special Issue on ATM networks,
Vol. XLVII, Jan-Feb 1996, pp.46-51
L. Jereb, T. V. Do, G. Wolfner,
``Analytical and Simulation Results on GCRA-based Traffic Shaping'',
Journal on Communications, Special Issue on ATM networks,
Vol. XLVII, Jan-Feb 1996
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``Some Simulation Results about Shaped TCP Connections in ATM
Networks'', in: D.Kouvatsos (editor),
Performance Modelling and Evaluation of ATM
Networks - Vol.2, Chapman and Hall, London, 1996
M. Ajmone Marsan, A. Bianco, A. Francini, R. Lo Cigno,
M.Munafò,
``Integrated Cell and Call Level Simulation of ATM Networks'',
Fourth Workshop on Performance Modeling and Evaluation of ATM Networks,
Ilkley, West Yorkshire, U.K., July 1996
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``A Comparison of Classical Control Techniques for EFCI ABR
Connections'',
Fourth Workshop on Performance Modeling and Evaluation of ATM Networks,
Ilkley, West Yorkshire, U.K., July 1996
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``TCP Over ABR in ATM Networks with Variable Topology and Background
Traffic'',
IEEE ATM Workshop 1996, San Francisco, CA, USA, August 1996
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``A Simulation Study of the Performance of TCP over the ABR and ABT ATM
Transfer Capability'',
8th IEEE Workshop on Local and Metropolitan Area Networks,
Postdam, Germany, August 1996
M. Ajmone Marsan, M. Baldi, A. Bianco, R. Lo Cigno, M. Munafò,
``Simulation Analysis of TCP and XTP File Transfers in ATM
Networks'',
5th IFIP Workshop on Protocol for High Speed Networks,
Sophia Antipolis, France, October 1996
M. Ajmone Marsan, A. Bianco, R. Lo Cigno, M. Munafò,
``Four Standard Control Theory Approaches
for the Implementation of RRM ABR Services'',
in: D.Kouvatsos (editor), Performance Modelling and Evaluation of ATM
Networks - Vol.3, Chapman and Hall, London, 1997
M. Ajmone Marsan, K. Begain, R. Lo Cigno, M. Munafò,
``Performance of TCP File Transfers over the Explicit Rate ABR
ATM Service Category'',
5th International Conference on Telecommunication Systems
Modelling and Analysis, March 20-23, 1997, Nashville, TN, USA
M. Ajmone Marsan, C.F. Chiasserini, A. Fumagalli, R. Lo Cigno,
M. Munafò,
``Buffer Requirements for Loss-Free Handovers in Wireless ATM
Networks'',
IEEE ATM'97 Workshop, Lisboa, Portugal, May 26-28, 1997
M. Ajmone Marsan, C.F. Chiasserini, A. Fumagalli, R. Lo Cigno,
M.Munafò,
``Local and Global Handover Based on In-Band Signaling
in Wireless ATM Networks'', Workshop on Nomadic Computing
Satellite of IPPS'97, Geneva, Switzerland, April 5 1997
M. Ajmone Marsan, A. Bianco, C. Casetti, C.F. Chiasserini,
A. Francini, R. Lo Cigno, M. Mellia, M.Munafò,
``An Integrated Software Environment for the Simulation of ATM
Networks'',
1997 Summer Computer Simulation Conference, July 13-17, 1997,
Key Bridge Marriot, Arlington, Virginia, USA
C.F. Chiasserini, R. Lo Cigno, M. Munafò,
``On the Implementation of Mobility Services in CLASS: Architecture,
Validation and Results'',
Fifth IFIP Workshop on Performance Modelling and Evaluation of ATM
Networks, Ilkley, U.K., 21st-23rd July, 1997
M. Ajmone Marsan, A. Bianco, C. Casetti, P. Castelli, R. Lo Cigno,
M. Mellia, M. Munafò,
``A Simulation Analysis of a QoS-Based CAC Algorithm for ATM
Networks'',
Fifth IFIP Workshop on Performance Modelling and Evaluation of ATM
Networks, Ilkley, U.K., 21st-23rd July, 1997
M. Ajmone Marsan, C.F. Chiasserini, A. Fumagalli, R. Lo Cigno,
M. Munafò,
``Local and Global Handovers for Mobility Management in Wireless ATM
Networks'',
IEEE Personal Communications - Special Issue on Mobility and Location:
A European Perspective, Vol. 4, No. 5, pp. 16-24, October 1997
M. Ajmone Marsan, M. Baldi, A. Bianco, R. Lo Cigno, M. Munafò,
``On the Performance of Transport Protocols Over ATM Networks'',
International Conference for Computer Communications - ICCC'97,
Cannes, France, Nov. 19-21, 1997
M. Ajmone Marsan, A. Bianco, C. Casetti, C.F. Chiasserini,
A. Francini, R. Lo Cigno, M. Munafò,
``An Integrated Simulation Environment for the Analysis of ATM
Networks at Multiple Time Scales'',
International Journal of Computer Networks and ISDN Systems,
Special Issue: Modeling of Wired and Wireless ATM Networks, 1997
M. Ajmone Marsan, K. Begain, R. Lo Cigno, M. Munafò,
``Stop & Go ABR: A Simple Algorithm for the Implementation of Best
Effort Services in ATM LANs'',
Fourth International Conference on Broadband Communications '98,
Stuttgart, Germany, April 1-3, 1998
M. Ajmone Marsan, A. Bianco, C. Casetti, P. Castelli, C.F. Chiasserini,
A. Francini, R. Lo Cigno, M. Mellia, M. Munafò,
``Variable Time Scale Simulation of ATM Traffic Control Techniques'',
5th Polish Teletraffic Symposium, Warsaw, Poland, April 1998
M. Ajmone Marsan, C.F. Chiasserini, A. Fumagalli, R. Lo Cigno,
M. Munafò,
``Local and Global Handovers Based on In-Band Signaling in
Wireless ATM Networks'',
ACM Mobile Computing and Communication Review, Vol. 2, No. 3, pp. 28-36,
July 1998
M. Ajmone Marsan, R. Lo Cigno, M. Munafò, C. Tironi,
``Dynamic Max-Min Fair Bandwidth Share in a Multi-Bottleneck ATM
Network'',
Third IFIP Workshop on Traffic Management and Design of ATM Networks,
London, U.K., April 26-27, 1999
For further information you can contact the CLASS Management Group at
