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Achieving interoperability between two domains : connecting the ZOTnet and UUCP computer mail networks
Important Lessons Derived from X.500 Case Studies
X.500 is a new and complex electronic directory technology, whose basic specification was first published as an international standard in 1988, with an enhanced revision in 1993. The technology is still unproven in many organisations. This paper presents case studies of 15 pioneering pilot and operational X.500 based directory services. The paper provides valuable insights into how organisations are coming to understand this new technology, are using X.500 for both traditional and novel directory based services, and consequently are deriving benefits from it. Important lessons that have been learnt by these X.500 pioneers are presented here, so that future organisations can benefit from their experiences. Factors critical to the success of implementing X.500 in an organisation are derived from the studies
Introduction to Directory Services
The Directory has grown to be an important OSI application as it acts as a focal point and general support for a number of other applications. This work first points out directory requirements in the OSI framework and other OSI applications, as the Mail Handling System. The first version of the X.500 standard is then described and some Directory related issues are discussed. In particular, X.500 Directory as a database system is examined and some directory service implementations are presented
OSI in the NASA science internet: An analysis
The Open Systems Interconnection (OSI) protocol suite is a result of a world-wide effort to develop international standards for networking. OSI is formalized through the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). The goal of OSI is to provide interoperability between network products without relying on one particular vendor, and to do so on a multinational basis. The National Institute for Standards and Technology (NIST) has developed a Government OSI Profile (GOSIP) that specified a subset of the OSI protocols as a Federal Information Processing Standard (FIPS 146). GOSIP compatibility has been adopted as the direction for all U.S. government networks. OSI is extremely diverse, and therefore adherence to a profile will facilitate interoperability within OSI networks. All major computer vendors have indicated current or future support of GOSIP-compliant OSI protocols in their products. The NASA Science Internet (NSI) is an operational network, serving user requirements under NASA's Office of Space Science and Applications. NSI consists of the Space Physics Analysis Network (SPAN) that uses the DECnet protocols and the NASA Science Network (NSN) that uses TCP/IP protocols. The NSI Project Office is currently working on an OSI integration analysis and strategy. A long-term goal is to integrate SPAN and NSN into one unified network service, using a full OSI protocol suite, which will support the OSSA user community
Mobility and Handoff Management in Wireless Networks
With the increasing demands for new data and real-time services, wireless
networks should support calls with different traffic characteristics and
different Quality of Service (QoS)guarantees. In addition, various wireless
technologies and networks exist currently that can satisfy different needs and
requirements of mobile users. Since these different wireless networks act as
complementary to each other in terms of their capabilities and suitability for
different applications, integration of these networks will enable the mobile
users to be always connected to the best available access network depending on
their requirements. This integration of heterogeneous networks will, however,
lead to heterogeneities in access technologies and network protocols. To meet
the requirements of mobile users under this heterogeneous environment, a common
infrastructure to interconnect multiple access networks will be needed. In this
chapter, the design issues of a number of mobility management schemes have been
presented. Each of these schemes utilizes IP-based technologies to enable
efficient roaming in heterogeneous network. Efficient handoff mechanisms are
essential for ensuring seamless connectivity and uninterrupted service
delivery. A number of handoff schemes in a heterogeneous networking environment
are also presented in this chapter.Comment: 28 pages, 11 figure
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