users that all data exists and is processed on their local workstations. An efficient NFS network also gives the right people access to the right amount of data at the right times.

Files and directories can be made available to clients by exporting from the server and mounting on clients through a pervasive NFS client/server relationship. An NFS client can also, at the same time, function as an NFS server, just as an NFS server can function as a client.

Stateless Network Protocol

NFS incorporates the Remote Procedure Call (RPC) for client/server communication. RPC is a high-end network protocol that encompasses many simpler protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).

NFS is a stateless protocol, maintaining absolutely no saved or archived information from client/server communications. State is the information regarding a request that describes exactly what the request does. A stateful protocol saves information about users and requests for use with many procedures. Statelessness is a condition where no information is retained about users and their requests. This condition demands that the information surrounding a request be sent with every single request. Due to NFS statelessness, each RPC request contains all the required information for the client and server to process user requests.

By using NFS, AS/400 users can bypass the details of the network interface. NFS isolates applications from the physical and logical elements of data communications and allows applications to use a variety of different transports.

In short, the NFS protocol is useful for applications that need to transfer information over a client/server network. For more information about RPC and NFS, see ªNetwork File System Stack Descriptionº on page 8.

Overview of the TULAB Scenario

This book uses the ®ctional namespaceTULAB to describe detailed applications of NFS concepts. A namespace is a distributed network space where one or more servers look up, manage, and share ordered, deliberate object names.

TULAB exists only in a hypothetical computer-networked environment at a ®ctitious Technological University. It is run by a network administrator, a person who de®nes the network con®guration and other network-related information. This person controls how an enterprise or system uses its network resources. The TULAB administrator, Chris Admin, is trying to construct an efficient, transparent, and otherwise seamless distributed namespace for the diverse people who use the

TULAB:

vEngineering undergraduate students

vHumanities undergraduate students

vEngineering graduate students

vTULAB consultants

4OS/400 Network File System Support V4R4

Page 22
Image 22
IBM AS/400E manual Stateless Network Protocol, Overview of the Tulab Scenario

AS/400E specifications

The IBM AS/400E, now more commonly known as IBM i, is a robust and versatile midrange server that has been designed to provide a comprehensive computing solution for businesses of all sizes. First introduced in the late 1980s, the AS/400 series has undergone multiple enhancements and rebranding, with the AS/400E being one of the notable iterations. This powerful platform is closely associated with IBM's commitment to reliability, scalability, and integrated business solutions.

One of the main features of the AS/400E is its highly integrated architecture that combines hardware and software into a cohesive system. This integration allows for seamless operations, reducing the complexity typically associated with managing disparate systems. The system is powered by IBM's proprietary OS/400 operating system, which has evolved into IBM i, featuring advanced capabilities like object-oriented programming, integrated database management, and security features that are essential for enterprise environments.

A key characteristic of the AS/400E is its robust database support, primarily through the use of DB2 for i. This integrated database management system enables efficient data handling and retrieval, facilitating real-time business analytics and reporting. Furthermore, the platform supports a variety of programming languages, including RPG, COBOL, and Java, making it flexible for developers who require diverse tools for application development.

The AS/400E is also known for its exceptional reliability and uptime, making it a preferred choice for critical business applications in industries such as finance, healthcare, and manufacturing. This reliability is backed by advanced error detection and correction mechanisms, as well as redundancy features that help prevent data loss and minimize downtime.

In terms of scalability, the AS/400E can effortlessly expand to accommodate growing business demands. Organizations can increase processing power by adding more resources without significant disruption. This scalability, combined with the system’s built-in virtualization capabilities, allows businesses to optimize resource usage and streamline operations.

Security is another defining feature of the AS/400E. The platform incorporates various layers of security measures, including user authentication, encryption, and comprehensive auditing capabilities, ensuring that sensitive business data is protected against unauthorized access.

Overall, the IBM AS/400E remains a powerful tool in the enterprise computing landscape, providing businesses with an integrated, reliable, and secure solution for their technological needs. Its enduring popularity is a testament to its capability to evolve with changing business requirements while maintaining its core attributes of high performance and stability.