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Jonathan Billington - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of the Datagram Congestion Control Protocol’s Connection Management procedures using the sweep-line method
    International Journal on Software Tools for Technology Transfer, 2008
    Co-Authors: Somsak Vanit-anunchai, Jonathan Billington, Guy Edward Gallasch
    Abstract:

    State space explosion is a key problem in the analysis of finite state systems. The sweep-line method is a state exploration method which uses a notion of progress to allow states to be deleted from memory when they are no longer required. This reduces the peak number of states that need to be stored, while still exploring the full state space. The technique shows promise but has never achieved reductions greater than about a factor of 10 in the number of states stored in memory for industrially relevant examples. This paper discusses sweep-line analysis of the Connection Management procedures of a new Internet standard, the Datagram Congestion Control Protocol (DCCP). As the intuitive approaches to sweep-line analysis are not effective, we introduce new variables to track progress. This creates further state explosion. However, when used with the sweep-line, the peak number of states is reduced by over two orders of magnitude compared with the original. Importantly, this allows DCCP to be analysed for larger parameter values.

  • Modelling and analysing the functional behaviour of TCP’s Connection Management procedures
    International Journal on Software Tools for Technology Transfer, 2007
    Co-Authors: Jonathan Billington, Bing Han
    Abstract:

    The transmission control protocol (TCP) is the most widely used transport protocol in the Internet. It provides a reliable data transfer service to many applications. In this paper, Coloured Petri Nets are used to model TCP’s Connection Management procedures. The model is created to verify TCP’s functional correctness (e.g. the absence of deadlocks and livelocks). We discuss different modelling approaches to motivate the approach taken. The paper defines the termination property of TCP’s Connection Management procedures, including the notions of desired and acceptable terminal states. Finally, we analyse TCP’s Connection Management procedures operating over re-ordering non-lossy and lossy channels. This is done incrementally and considers 11 different configurations. The analysis provides some insights into TCP’s behaviour where in certain circumstances the protocol fails to establish or terminate successfully.

  • ICFEM - Sweep-Line analysis of TCP Connection Management
    Formal Methods and Software Engineering, 2005
    Co-Authors: Guy Edward Gallasch, Jonathan Billington
    Abstract:

    Despite the widespread use of the Transmission Control Protocol (TCP) as the main transport protocol in the Internet, the procedures for Connection establishment and release are still not fully understood. This paper extends the analysis of a Coloured Petri net model of TCP’s Connection Management procedures by applying the state explosion alleviation technique known as the sweep-line method. The protocol is assumed to be operating over a reordering lossless channel. Termination and absence of deadlock properties are investigated for many scenarios, including client-server and simultaneous Connection establishment, orderly release and abortion. The sweep-line method provides a reduction in memory usage of around a factor of 10 and allows investigation of many scenarios that were previously out of the reach of conventional methods.

  • ICATPN - Termination properties of TCP's Connection Management procedures
    Applications and Theory of Petri Nets 2005, 2005
    Co-Authors: Jonathan Billington
    Abstract:

    The Transmission Control Protocol (TCP) is the most widely used transport protocol in the Internet, providing a reliable data transfer service to many applications. This paper analyses TCP's Connection Management procedures for correct termination and absence of deadlocks. The protocol is assumed to be operating over a reordering lossless channel and is modelled using Coloured Petri nets. The following Connection Management scenarios are examined using state space analysis: client-server and simultaneous opening; orderly release; and abortion. The results demonstrate that TCP terminates correctly for client-server and simultaneous Connection establishment, orderly release after the Connection is established and aborting of Connections. However, we discover a deadlock when Connection release is initiated before the Connection has been fully established when operating over a reordering lossless channel.

  • ICATPN - Modelling the datagram congestion control protocol's Connection Management and synchronization procedures
    Petri Nets and Other Models of Concurrency – ICATPN 2007, 1
    Co-Authors: Somsak Vanit-anunchai, Jonathan Billington
    Abstract:

    The Datagram Congestion Control Protocol (DCCP) is a new transport protocol standardised by the Internet Engineering Task Force in March 2006. This paper specifies the Connection Management and synchronisation procedures of DCCP using Coloured Petri nets (CPNs). After introducing the protocol, we describe how the CPN model has evolved as DCCP was being developed. We focus on our experience of incremental enhancement and iterative modelling in the hope that this will provide guidance to those attempting to build complex protocol models. In particular we discuss how the architecture, data structures and specification style of the model have evolved as DCCP was developed. The impact of this work on the DCCP standard is also briefly discussed.

Guy Edward Gallasch - One of the best experts on this subject based on the ideXlab platform.

  • Analysis of the Datagram Congestion Control Protocol’s Connection Management procedures using the sweep-line method
    International Journal on Software Tools for Technology Transfer, 2008
    Co-Authors: Somsak Vanit-anunchai, Jonathan Billington, Guy Edward Gallasch
    Abstract:

    State space explosion is a key problem in the analysis of finite state systems. The sweep-line method is a state exploration method which uses a notion of progress to allow states to be deleted from memory when they are no longer required. This reduces the peak number of states that need to be stored, while still exploring the full state space. The technique shows promise but has never achieved reductions greater than about a factor of 10 in the number of states stored in memory for industrially relevant examples. This paper discusses sweep-line analysis of the Connection Management procedures of a new Internet standard, the Datagram Congestion Control Protocol (DCCP). As the intuitive approaches to sweep-line analysis are not effective, we introduce new variables to track progress. This creates further state explosion. However, when used with the sweep-line, the peak number of states is reduced by over two orders of magnitude compared with the original. Importantly, this allows DCCP to be analysed for larger parameter values.

  • ICFEM - Sweep-Line analysis of TCP Connection Management
    Formal Methods and Software Engineering, 2005
    Co-Authors: Guy Edward Gallasch, Jonathan Billington
    Abstract:

    Despite the widespread use of the Transmission Control Protocol (TCP) as the main transport protocol in the Internet, the procedures for Connection establishment and release are still not fully understood. This paper extends the analysis of a Coloured Petri net model of TCP’s Connection Management procedures by applying the state explosion alleviation technique known as the sweep-line method. The protocol is assumed to be operating over a reordering lossless channel. Termination and absence of deadlock properties are investigated for many scenarios, including client-server and simultaneous Connection establishment, orderly release and abortion. The sweep-line method provides a reduction in memory usage of around a factor of 10 and allows investigation of many scenarios that were previously out of the reach of conventional methods.

Kai Y Eng - One of the best experts on this subject based on the ideXlab platform.

  • mobility and Connection Management in a wireless atm lan
    IEEE Journal on Selected Areas in Communications, 1997
    Co-Authors: Malathi Veeraraghavan, M J Karol, Kai Y Eng
    Abstract:

    This paper proposes algorithms for handoff, location, and Connection Management in a wireless asynchronous transfer mode (ATM) local-area network (LAN). Fast handoffs while maintaining cell sequence and quality-of-service (QoS) guarantees are achieved by distributing switching functionality to base stations, and using a networking scheme based on provisioned virtual trees. A new distributed location Management scheme using a minimal registration procedure and broadcasts on wired links is proposed for this LAN. The detailed signaling procedures that support the algorithms for mobility and Connection Management are described. Finally, an implementation of these procedures and an analysis of the measured data is presented. Measurements of service times obtained from this implementation indicate that over 100 calls/s. can be handled by each node in 50-node network with a high-percentage of mobiles (75%) relative to fixed endpoints. This is comparable to current wired ATM switch call handling throughputs, in spite of the fact that these nodes perform additional handoff and location Management functions. The data also indicates handoff latency times of 1.3 ms. This validates our proposal for maintaining cell sequence while performing handoffs.

  • Implementation and analysis of Connection-Management procedures in a wireless ATM LAN
    Proceedings of ICUPC - 5th International Conference on Universal Personal Communications, 1
    Co-Authors: Malathi Veeraraghavan, M J Karol, Kai Y Eng
    Abstract:

    In a previous paper, we proposed a wireless ATM (asynchronous transfer mode) LAN (local area network) with two features to simplify handoffs: distributed switching/buffering at base stations, and provisioned destination-rooted trees. In this paper, we describe an end-to-end handshake-based Connection-Management algorithm, and a distributed location-Management algorithm for this wireless ATM LAN. An implementation of these algorithms and the service time measurements obtained from the implementation are described. This data is used to perform a throughput analysis, which indicates that over 100 calls/sec can be handled by each node in typical configurations, which is comparable to current wired ATM switch call handling throughputs, in spite of the fact that these nodes perform additional location Management and handoff functions. Finally, we present a signaling bandwidth analysis to demonstrate the feasibility of the distributed location Management scheme in LANs.

Malathi Veeraraghavan - One of the best experts on this subject based on the ideXlab platform.

  • mobility and Connection Management in a wireless atm lan
    IEEE Journal on Selected Areas in Communications, 1997
    Co-Authors: Malathi Veeraraghavan, M J Karol, Kai Y Eng
    Abstract:

    This paper proposes algorithms for handoff, location, and Connection Management in a wireless asynchronous transfer mode (ATM) local-area network (LAN). Fast handoffs while maintaining cell sequence and quality-of-service (QoS) guarantees are achieved by distributing switching functionality to base stations, and using a networking scheme based on provisioned virtual trees. A new distributed location Management scheme using a minimal registration procedure and broadcasts on wired links is proposed for this LAN. The detailed signaling procedures that support the algorithms for mobility and Connection Management are described. Finally, an implementation of these procedures and an analysis of the measured data is presented. Measurements of service times obtained from this implementation indicate that over 100 calls/s. can be handled by each node in 50-node network with a high-percentage of mobiles (75%) relative to fixed endpoints. This is comparable to current wired ATM switch call handling throughputs, in spite of the fact that these nodes perform additional handoff and location Management functions. The data also indicates handoff latency times of 1.3 ms. This validates our proposal for maintaining cell sequence while performing handoffs.

  • Implementation and analysis of Connection-Management procedures in a wireless ATM LAN
    Proceedings of ICUPC - 5th International Conference on Universal Personal Communications, 1
    Co-Authors: Malathi Veeraraghavan, M J Karol, Kai Y Eng
    Abstract:

    In a previous paper, we proposed a wireless ATM (asynchronous transfer mode) LAN (local area network) with two features to simplify handoffs: distributed switching/buffering at base stations, and provisioned destination-rooted trees. In this paper, we describe an end-to-end handshake-based Connection-Management algorithm, and a distributed location-Management algorithm for this wireless ATM LAN. An implementation of these algorithms and the service time measurements obtained from the implementation are described. This data is used to perform a throughput analysis, which indicates that over 100 calls/sec can be handled by each node in typical configurations, which is comparable to current wired ATM switch call handling throughputs, in spite of the fact that these nodes perform additional location Management and handoff functions. Finally, we present a signaling bandwidth analysis to demonstrate the feasibility of the distributed location Management scheme in LANs.

A. U Shankar - One of the best experts on this subject based on the ideXlab platform.

  • Connection Management for the transport layer: service specification and protocol verification
    IEEE Transactions on Communications, 1991
    Co-Authors: S.l. Murphy, A. U Shankar
    Abstract:

    A symmetric Connection Management service between two service access points is specified, using a state transition system and safety and progress requirements. At each access point. the user can request Connection establishment, request Connection termination, and signal whether or not they are willing to accept Connection requests from the remote user. The protocol can indicate Connection establishment, Connection termination, and rejection of a Connection establishment request. The authors then specify a protocol and verify that it offers the service, given communication channels between the access points that can lose, reorder, and duplicate messages, but which guarantee delivery of a message that is repeatedly sent. The protocol achieves the service using 2-way and 3-way handshakes, and can be directly combined with any existing single-Connection data transfer protocols to provide a transport layer protocol that offers both Connection Management and data transfer services. The protocol and service are compared to TCP and its intended service, and to ISO TP Class 4 and its intended service.