Network management and control of protocols

Abstract

The management and control of multivendor, multidomain networks poses new problems in the development, analysis and diagnosis of protocols. Particular difficulties may arise in the combination, through gateways a n d converters, of existing well formed protocols, in that unplanned build ups of channel queues may occur in a n unsynchronized fashion. In this paper we describe some of the special requirements placed on protocols that must function in a multidomain environment. Subject to these requirements, we describe a new protocol structure called a "bipartite protocol" based upon the use of "tokens". We show that the use of bipartite protocols enables us to perform a number of functions, namely: 1) Systematically explore subgraphs of the global state diagram, representing the protocol, with predetermined numbers of messages in the channel queues, thereby facilitating the analysis of protocols. 2) Generate tightly synchronized protocols or sections of protocols, thereby controlling the build up of queues in the channels. 3) Implement sections of network control systems using the tokens in the bipartite protocol structure.Examples a r e given for X.75, illustrating both the analysis of protocols a n a the control of channel contents.