M. Ferguson, G. Bochmann, T. Radhakrishnan, G. Ratzer, Rebecca Hutchings
{"title":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","authors":"M. Ferguson, G. Bochmann, T. Radhakrishnan, G. Ratzer, Rebecca Hutchings","doi":"10.1145/800056","DOIUrl":"https://doi.org/10.1145/800056","url":null,"abstract":"","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"65 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123450408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The CIL-approach for the development of communication services is based on the programming language CIL (Communication Service Implementation Language) and a CIL-compatible theory of program execution. The theory contains a first-order predicate calculus and an event-oriented model of program execution. The verification of programs written in CIL is supported by the automated generation of program axioms and by an interactive theorem prover tailored to the predicate calculus. Interactive verification during the design phase leads to early detection and localization of design errors and helps to reduce the efforts for debugging and testing. The paper describes the principles of the language, the theory, and the interactive verification tool. The design of a program realizing a transport service exemplifies the CIL-approach.
{"title":"Interactive verification of communication software on the basis of CIL","authors":"H. Krumm, O. Drobnik","doi":"10.1145/800056.802065","DOIUrl":"https://doi.org/10.1145/800056.802065","url":null,"abstract":"The CIL-approach for the development of communication services is based on the programming language CIL (Communication Service Implementation Language) and a CIL-compatible theory of program execution. The theory contains a first-order predicate calculus and an event-oriented model of program execution. The verification of programs written in CIL is supported by the automated generation of program axioms and by an interactive theorem prover tailored to the predicate calculus. Interactive verification during the design phase leads to early detection and localization of design errors and helps to reduce the efforts for debugging and testing. The paper describes the principles of the language, the theory, and the interactive verification tool. The design of a program realizing a transport service exemplifies the CIL-approach.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"258 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123289157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper deals with a strategy for a development chain of protocols (specification, validation, conformity testing) based on knowledge of the RHIN project methodology and the tools which this project produced. This methodology is based on finite state machines with predicates and includes “conceptual” tools for specification (PDIL)and for validation (VADILOC). “Experimental” tools play a part in conformity testing (STQ, Cerbere, Genepi). The interaction between conceptual and experimental tools is provided by a test sequence generator GAST which, starting from an automaton whose communication has been validated, provides sequences to be used by the test tools.
{"title":"Some operational tools in a OSI protocols study environment","authors":"J. Ansart, O. Rafiq, R. Castanet, P. Guitton","doi":"10.1145/800056.802073","DOIUrl":"https://doi.org/10.1145/800056.802073","url":null,"abstract":"This paper deals with a strategy for a development chain of protocols (specification, validation, conformity testing) based on knowledge of the RHIN project methodology and the tools which this project produced. This methodology is based on finite state machines with predicates and includes “conceptual” tools for specification (PDIL)and for validation (VADILOC). “Experimental” tools play a part in conformity testing (STQ, Cerbere, Genepi). The interaction between conceptual and experimental tools is provided by a test sequence generator GAST which, starting from an automaton whose communication has been validated, provides sequences to be used by the test tools.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128994799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This contribution describes a new type of an integrated system's architecture which reconciles the diverging needs of both, stream traffic of 64 kbit/s and bursty traffic of low and high data rates. The total capacity of a unidirectional bus is subdivided into a high-speed channel and a certain number of time slots for stream traffic. The capacity of the high-speed channel can dynamically be adjusted according to the amount of time slots required for stream traffic. Due to the dynamic creation and deletion of time slots, the subsystem for 64-kbit/s channels is almost blocking-free. The same mechanism is used to control access to the high-speed channel, and to determine the fraction of the total capacity dedicated to the high-speed channel. The performance of the proposed access mechanism has been investigated by means of system modelling and simulation. The results show that besides its ability to accommodate 64-kbit/s channels it compares quite favourably with other LAN concepts like CSMA/CD.
{"title":"Performance analysis of an access method suitable for the integration of voice and data","authors":"J.-P. Behr, U. Killat","doi":"10.1145/800056.802075","DOIUrl":"https://doi.org/10.1145/800056.802075","url":null,"abstract":"This contribution describes a new type of an integrated system's architecture which reconciles the diverging needs of both, stream traffic of 64 kbit/s and bursty traffic of low and high data rates. The total capacity of a unidirectional bus is subdivided into a high-speed channel and a certain number of time slots for stream traffic. The capacity of the high-speed channel can dynamically be adjusted according to the amount of time slots required for stream traffic. Due to the dynamic creation and deletion of time slots, the subsystem for 64-kbit/s channels is almost blocking-free. The same mechanism is used to control access to the high-speed channel, and to determine the fraction of the total capacity dedicated to the high-speed channel. The performance of the proposed access mechanism has been investigated by means of system modelling and simulation. The results show that besides its ability to accommodate 64-kbit/s channels it compares quite favourably with other LAN concepts like CSMA/CD.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116187515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Computer systems can be &distributed& in many different senses - for example: the user access (such as remote terminals); the system geography (such as a computer network); the processing (such as a multiprocessor or a multicomputer); the data (such as a partitioned or a replicated database); the operating system (such as a network OS or a decentralized OS). These senses of distribution are not independent, and each has its own advantages and disadvantages in various circumstances, as well as its own research problems. However, some senses are becoming better understood than others, and some are becoming recognized as more fundamentally important than others. Distributing the user access or the system geography per se can be regarded as neither especially challenging nor critically fundamental technology. Distributing the (user portion of the) processing is important, and the ease of doing so is, to a first order approximation, determined by the extent and manner in which the data and operating system are distributed. It currently seems to be these latter two aspects of computing whose distribution involves the most essential, and difficult, new technology.
{"title":"Physically dispersing an operating system","authors":"E. Jensen","doi":"10.1145/800056.802088","DOIUrl":"https://doi.org/10.1145/800056.802088","url":null,"abstract":"Computer systems can be &distributed& in many different senses - for example: the user access (such as remote terminals); the system geography (such as a computer network); the processing (such as a multiprocessor or a multicomputer); the data (such as a partitioned or a replicated database); the operating system (such as a network OS or a decentralized OS). These senses of distribution are not independent, and each has its own advantages and disadvantages in various circumstances, as well as its own research problems. However, some senses are becoming better understood than others, and some are becoming recognized as more fundamentally important than others. Distributing the user access or the system geography per se can be regarded as neither especially challenging nor critically fundamental technology. Distributing the (user portion of the) processing is important, and the ease of doing so is, to a first order approximation, determined by the extent and manner in which the data and operating system are distributed. It currently seems to be these latter two aspects of computing whose distribution involves the most essential, and difficult, new technology.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126593457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an extension of the slotted ALOHA protocol for use in a spread spectrum packet radio environment. With spread spectrum, we assume that N distinct codes are available, and that each code can be treated as a separate channel. Running an independent copy of the protocol on each of these channels would be undesirable, since each user would have to select one channel to monitor for packets addressed to it, inducing a logical partitioning of the user population into N groups. To preserve the logical connectivity of the network, we examine the effect of separating packet transmissions into two parts, a short preamble, which is sent over a public channel, and followed by the body,> which is sent over a private channel. We assume that m of the available codes are used as preamble channels, and the remaining N - m codes are used for actual packet transmissions. If m (@@@@) N, then the network can support broadcast and multicast packets, and still make use of all of the available channels.
{"title":"On the performance of slotted ALOHA in a spread spectrum environment","authors":"P. Economopoulos, M. Molle","doi":"10.1145/800056.802083","DOIUrl":"https://doi.org/10.1145/800056.802083","url":null,"abstract":"We present an extension of the slotted ALOHA protocol for use in a spread spectrum packet radio environment. With spread spectrum, we assume that N distinct codes are available, and that each code can be treated as a separate channel. Running an independent copy of the protocol on each of these channels would be undesirable, since each user would have to select one channel to monitor for packets addressed to it, inducing a logical partitioning of the user population into N groups. To preserve the logical connectivity of the network, we examine the effect of separating packet transmissions into two parts, a short preamble, which is sent over a public channel, and followed by the body,> which is sent over a private channel. We assume that m of the available codes are used as preamble channels, and the remaining N - m codes are used for actual packet transmissions. If m (@@@@) N, then the network can support broadcast and multicast packets, and still make use of all of the available channels.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122776692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There are certain technical design principles for link communication protocols which, if followed, result in a protocol that is less complex in both concept and implementation, but at the same time provides better service, than if the principles are not followed. These principles include modularization into sub-protocols, symmetry between the nodes on the link, and use of the state-exchange model of a conversation rather than the command-response model. The principles are described, the extent to which they are followed by the standard protocol X.25, level 2, is examined, and a protocol adhering to them is presented.
{"title":"Serial link protocol design: A critique of the X.25 standard, level 2","authors":"J. G. Fletcher","doi":"10.1145/800056.802056","DOIUrl":"https://doi.org/10.1145/800056.802056","url":null,"abstract":"There are certain technical design principles for link communication protocols which, if followed, result in a protocol that is less complex in both concept and implementation, but at the same time provides better service, than if the principles are not followed. These principles include modularization into sub-protocols, symmetry between the nodes on the link, and use of the state-exchange model of a conversation rather than the command-response model. The principles are described, the extent to which they are followed by the standard protocol X.25, level 2, is examined, and a protocol adhering to them is presented.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114277562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A major reason for the rarity of distributed applications, despite the proliferation of networks, is the sensitivity of their performance to various aspects of the network environment. Contrary to much popular opinion, we demonstrate that CPU speed remains the predominant factor. With respect to network issues, we focus on two approaches to performance enhancement: (1) Improving the performance of reliable, byte-stream protocols such as TCP; (2) the use of high-level protocols that reduce the frequency and volume of communication.
{"title":"Factors affecting the performance of distributed applications","authors":"K. Lantz, W. I. Nowicki, M. Theimer","doi":"10.1145/800056.802068","DOIUrl":"https://doi.org/10.1145/800056.802068","url":null,"abstract":"A major reason for the rarity of distributed applications, despite the proliferation of networks, is the sensitivity of their performance to various aspects of the network environment. Contrary to much popular opinion, we demonstrate that CPU speed remains the predominant factor. With respect to network issues, we focus on two approaches to performance enhancement: (1) Improving the performance of reliable, byte-stream protocols such as TCP; (2) the use of high-level protocols that reduce the frequency and volume of communication.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130837682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Protocol execution can run into bottlenecks which are due to implementation decisions rather than to the protocol rules. The performance effects of processor saturation, buffer management strategy, allocation of functions between host and front-end, and hardware-software interactions due to special hardware attributes can, in principle, be predicted at the design stage by analytic performance models. The paper describes the process of construction of such a model for the data transfer stage of a simple transport protocol resembling an OSI class 4 protocol, including queueing for critical sections which protect the buffer pools and connection state information. The model is part of a computer-aided design process for communications systems, currently under development.
{"title":"A performance model for hardware/software issues in computer-aided design of protocol systems","authors":"C. Woodside, J. Montealegre, R. Buhr","doi":"10.1145/800056.802070","DOIUrl":"https://doi.org/10.1145/800056.802070","url":null,"abstract":"Protocol execution can run into bottlenecks which are due to implementation decisions rather than to the protocol rules. The performance effects of processor saturation, buffer management strategy, allocation of functions between host and front-end, and hardware-software interactions due to special hardware attributes can, in principle, be predicted at the design stage by analytic performance models. The paper describes the process of construction of such a model for the data transfer stage of a simple transport protocol resembling an OSI class 4 protocol, including queueing for critical sections which protect the buffer pools and connection state information. The model is part of a computer-aided design process for communications systems, currently under development.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"13 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120835756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The file distribution system on the Universe Network consists of a distributed set of co-operating agents which provide clients with a reliable bulk file collection, transfer and delivery service. The agent systems incorporate specialised techniques for optimizing use of the satellite channel, as well as making available facilities for broadcast file distribution. The distributed system architecture and protocols are described, with emphasis on the separation of control and data transfer. A detailed presentation is given of the way in which agents interact with both hosts and other agents to achieve both reliability and robustness in the face of breaks in host or network availability. A description is given of the special transfer methods used and some of the possible applications for such a system. An indication is given of possible future developments to enable evolution from an experimental to service system.
{"title":"Managed file distribution on the universe network","authors":"C. Cooper","doi":"10.1145/800056.802054","DOIUrl":"https://doi.org/10.1145/800056.802054","url":null,"abstract":"The file distribution system on the Universe Network consists of a distributed set of co-operating agents which provide clients with a reliable bulk file collection, transfer and delivery service. The agent systems incorporate specialised techniques for optimizing use of the satellite channel, as well as making available facilities for broadcast file distribution. The distributed system architecture and protocols are described, with emphasis on the separation of control and data transfer. A detailed presentation is given of the way in which agents interact with both hosts and other agents to achieve both reliability and robustness in the face of breaks in host or network availability. A description is given of the special transfer methods used and some of the possible applications for such a system. An indication is given of possible future developments to enable evolution from an experimental to service system.","PeriodicalId":197970,"journal":{"name":"Proceedings of the ACM SIGCOMM symposium on Communications architectures and protocols: tutorials & symposium","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1984-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130320248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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