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Integration of Local Area Networks Into Rscs-Based Networks

IP.com Disclosure Number: IPCOM000039826D
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 4 page(s) / 53K

Publishing Venue

IBM

Related People

Hauser, RF: AUTHOR

Abstract

This article describes a concept for the integration of a Local Area Network (LAN) including personal computers or workstations into RSCS- based networks. To access RSCS-based networks, personal computer (PC) or workstation users need currently personal user accounts on a time-sharing host system (e.g., a VM system or a TSO system). Hosts and PCs cooperate in a master-slave relationship, and the PCs more or less emulate normal terminals. A more recent approach is to use LANs instead of host-dominated star systems. However, the question is whether or not LANs can be integrated into RSCS-based networks, since RSCS-based networks are conceptually based on time-sharing host systems, while LANs connect intelligent and usually single-user machines with very different concepts. Time-sharing systems can be interpreted as virtual LANs.

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Integration of Local Area Networks Into Rscs-Based Networks

This article describes a concept for the integration of a Local Area Network (LAN) including personal computers or workstations into RSCS- based networks. To access RSCS-based networks, personal computer (PC) or workstation users need currently personal user accounts on a time-sharing host system (e.g., a VM system or a TSO system). Hosts and PCs cooperate in a master-slave relationship, and the PCs more or less emulate normal terminals. A more recent approach is to use LANs instead of host-dominated star systems. However, the question is whether or not LANs can be integrated into RSCS-based networks, since RSCS-based networks are conceptually based on time-sharing host systems, while LANs connect intelligent and usually single-user machines with very different concepts. Time-sharing systems can be interpreted as virtual LANs. Especially VM systems for which RSCS-based networks have been dsigned are well-suited for this interpretation. The control program (CP) of the VM system represents a virtual LAN and some other services. The virtual machines represent the user machines attached to the virtual LAN. The Inter-User Communication Vehicle (IUCV) is one of the com munication facilities on the virtual LAN. The figure visualizes this interpretation. The whole LAN or part of it with all its PCs or workstations represents a node (with a node-id) of the RSCS-based network. The PCs or workstations represent user machines (with a user-id) in analogy to virtual machines in VM systems. The whole LAN or part of it should represent an RSCS node and not single user machines. Authentication requires logon/logoff procedures. Also other CP services available on VM systems have to be provided: Since file transfer communication between user virtual machines and RSCS virtual machines is based on spool-file exchange which is not available on LANs, an appropriate protocol (called submission/delivery protocol) has to be defined to replace this spool-file exchange protocol. A submission and delivery protocol for communication between the RSCS-LAN gateway and the user machine is presented below. It can be implemented on top of many different LAN protocols, but the OSI transport protocol has been chosen as an example. LOGON and LOGOFF A LOGON and a LOGOFF function are needed in order to allow authentication and subsequent reception of the asynchronous messages (datagram messages) sent by RSCS via the RSCS-LAN gateway. If a user wants to get all these messages, he will need a permanent connection to the gateway. When a user is not logged on, all these messages are discarded, and the sender is informed accordingly. These two functions correspond to the similar functions available on VM systems, but they have a different purpose.

In VM, the LOGON function gives access to all virtual-machine facilities, while a PC user gets local machine facilities without LOGON. The two functions LOGON and LOGOFF ar...