Description of protocols implemented in the SGB network

Abstract

This paper describes the different levels of protocols implemented in the future network of the Société Générale de Banque (SGB) Belgium. They are implemented in a front-end computer interfacing the host computer and the network that will be conform to the CCITT X25 standards. The various software modules are a Network Communication Manager: the transport station, a Network Interface Task dialoguing with a remote correspondent, a Host Interface Task talking with the application program in the host via a channel emulator. The exchange of data inside the front-end computer and storing on disks is managed by the module “Enqueue-Dequeue”. Data exchange between host and his correspondent can be either asynchronous with an intermediate storing in the front-end or synchronous as in transaction mode. In the first case the recovery procedures are ensured by Enqueue-Dequeue, in the latter case the recovery is under responsibility of the corresponding application programs. This article is complemented by the paper on the transport station.