- Email: [email protected]
Fails to reflect current thinking?
books continued from p. 657
support for heterogeneity could also have been used as a major criterion. Moreover, no description of what object-oriented means in the specific context of distributed systems is provided; e.g. some authors would classify more of the systems only as object-based (no inheritance supported). Others require suport for fine-grained objects to classift/ a distributed system as object-based. Several tables of comparison are given after the main chapters; this information might be even more important for many readers. The criteria of comparison (e.g. levels of distribution transparency, support for heterogeneity, communicaiton mechanisms, naming, security, and fault-tolerance) and their instantiation have been carefully selected and analysed by the author. In some instances, it is hard to stay in the strict classification scheme (e.g. concerning communication semantics); perhaps the table entries should sometimes indicate this problem. The same criteria have been used for comparing file systems and operating systems. While this supports a uniform presentation, the semantics might have been represented much better if they had been based on different criteria, e.g. file caching or concurrent file update semantics are important issues for distributed file systems, but much less for general distributed operating systems. In summary, these minor problems are largely outweighed by the outstanding breadth and depth of the material covered in the book. The author's claim to give a systematic and almost 658
complete survey of the dis- ested in such a technical distributed file/operating sys- tributed systems survey. tems area has been fully met. The book can be recDr Alexander Schill ommended without any University of Karlsruhe, reservation to those interGermany
Fails to reflect current thinking? The ISDN concept started to discussed, and is inserted in emerge with the transition of an understandable context. the industrial society to an Perhaps more examples and information society. In this figures would have helped context, new applications readers. are identified at a very rapid The chapters are generally rate, and the traditional net- self-contained, and are preworking approach based on sented in a sequence that dedicated, application-spe- allows reader's to progress cific networks can no longer from basic concepts to sersupport such a quickly vices and technologies. A changing service scenario. preliminary chapter reviews A book dealing with ISDN the basic concepts of digital has the difficult task of technology, emphasizing the taking into account the sub- principles of transmitting and ject's continuous evolution; receiving signals over various what today appears as estab- communication channels. lished, tomorrow could be The core of the book is a outdated. In this sense the description of the physical, authors claim that there is, electrical and signalling interat this time, sufficient knowl- faces. Both the basic and priedge that will remain intact mary accesses are discussed, for the foreseeable future, together with the ISDN usereven though advances in network interface signalling ISDN technology continue. protocols, and reference is A chapter therefore describes made to the SS7 protocol and the evolutionary trends its interworking with usertowards futuristic scenarios network interface protocols. of broadband functionalities Two chapters discuss (B-ISDN) and multimedia applications, particularly capabilities. emerging services and the This book is oriented more sophisticated future towards communication applications of multimedia engineers and specialists in and intelligent networks. networking, and provides Some ideas on the insertion appropriate background and of the broadband capabilities a wide overview of the field. in the ISDN concept are then All subjects are clearly c~iVen; however, the book approached. Obviously, conoes not reflect the work stant reference is made to the currently being carried out in CClTT's I and Q series rec- this area. Moreover, some ommendations. An overview concepts have now been of the ISDN standardization overtaken by progress in process is given, and the standardization activities. standards forums and legislative procedures employed Dr Marco Listanti are reviewed. The text of the Universita' di Roma, recommendations is widely Italy
ISDN Systems: Architecture, Technology and Applications edited b y K Verma Prentice Hall, UK (1990), 354pp, £62.05
computer communications
support for heterogeneity could also have been used as a major criterion. Moreover, no description of what object-oriented means in the specific context of distributed systems is provided; e.g. some authors would classify more of the systems only as object-based (no inheritance supported). Others require suport for fine-grained objects to classift/ a distributed system as object-based. Several tables of comparison are given after the main chapters; this information might be even more important for many readers. The criteria of comparison (e.g. levels of distribution transparency, support for heterogeneity, communicaiton mechanisms, naming, security, and fault-tolerance) and their instantiation have been carefully selected and analysed by the author. In some instances, it is hard to stay in the strict classification scheme (e.g. concerning communication semantics); perhaps the table entries should sometimes indicate this problem. The same criteria have been used for comparing file systems and operating systems. While this supports a uniform presentation, the semantics might have been represented much better if they had been based on different criteria, e.g. file caching or concurrent file update semantics are important issues for distributed file systems, but much less for general distributed operating systems. In summary, these minor problems are largely outweighed by the outstanding breadth and depth of the material covered in the book. The author's claim to give a systematic and almost 658
complete survey of the dis- ested in such a technical distributed file/operating sys- tributed systems survey. tems area has been fully met. The book can be recDr Alexander Schill ommended without any University of Karlsruhe, reservation to those interGermany
Fails to reflect current thinking? The ISDN concept started to discussed, and is inserted in emerge with the transition of an understandable context. the industrial society to an Perhaps more examples and information society. In this figures would have helped context, new applications readers. are identified at a very rapid The chapters are generally rate, and the traditional net- self-contained, and are preworking approach based on sented in a sequence that dedicated, application-spe- allows reader's to progress cific networks can no longer from basic concepts to sersupport such a quickly vices and technologies. A changing service scenario. preliminary chapter reviews A book dealing with ISDN the basic concepts of digital has the difficult task of technology, emphasizing the taking into account the sub- principles of transmitting and ject's continuous evolution; receiving signals over various what today appears as estab- communication channels. lished, tomorrow could be The core of the book is a outdated. In this sense the description of the physical, authors claim that there is, electrical and signalling interat this time, sufficient knowl- faces. Both the basic and priedge that will remain intact mary accesses are discussed, for the foreseeable future, together with the ISDN usereven though advances in network interface signalling ISDN technology continue. protocols, and reference is A chapter therefore describes made to the SS7 protocol and the evolutionary trends its interworking with usertowards futuristic scenarios network interface protocols. of broadband functionalities Two chapters discuss (B-ISDN) and multimedia applications, particularly capabilities. emerging services and the This book is oriented more sophisticated future towards communication applications of multimedia engineers and specialists in and intelligent networks. networking, and provides Some ideas on the insertion appropriate background and of the broadband capabilities a wide overview of the field. in the ISDN concept are then All subjects are clearly c~iVen; however, the book approached. Obviously, conoes not reflect the work stant reference is made to the currently being carried out in CClTT's I and Q series rec- this area. Moreover, some ommendations. An overview concepts have now been of the ISDN standardization overtaken by progress in process is given, and the standardization activities. standards forums and legislative procedures employed Dr Marco Listanti are reviewed. The text of the Universita' di Roma, recommendations is widely Italy
ISDN Systems: Architecture, Technology and Applications edited b y K Verma Prentice Hall, UK (1990), 354pp, £62.05
computer communications