Connectionless service handling with B-ISDN

The authors discuss the issues relevant to the definition of the connectionless (CL) service within B-ISDN (broadband ISDN). The direct provision of such a service is assumed. A functional network architecture, consisting of a CL virtual network and an ATM transport network, is proposed. This architecture allows a separate definition of CL service specific functionalities, realized by servers, from the handling of the ATM transport capabilities, which provide the server interconnection. The impact of the CL traffic characteristics on the allocation of the ATM network resources is analyzed, and guidelines for the connection handling are suggested. Specific CL data transfer functions are identified, taking into account the DQDB (distributed queue dual bus) protocol. Protocol data unit format and functions are introduced for the layer above the ATM adaptation layer. Finally, for the implementation of the CL protocol in the ATM based environment, two proposals relevant to the CL server operation mode are presented