Cluster Terminology?
SCS: Systems Communication Services. The protocol used to communicate between VMSCluster systems and between OpenVMS systems and SCS-based storage controllers. (SCSI-based storage controllers do not use SCS.) PORT: A communications device, such as DSSI, CI, Ethernet or FDDI. Each CI or DSSI bus is a different local port, named PAA0, PAB0, PAC0 etc. All Ethernet and FDDI busses make up a single PEA0 port. 15-12 Information on Networks and Clusters VIRTUAL CIRCUIT: A reliable communications path established between a pair of ports. Each port in a VMScluster establishes a virtual circuit with every other port in that cluster. All systems and storage controllers establish “Virtual Circuits” to enable communications between all available pairs of ports. SYSAP: A “system application” that communicates using SCS. Each SYSAP communicates with a particular remote SYSAP. Example SYSAPs include: VMS$DISK_CL_DRIVER connects to MSCP$DISK The disk class driver is on every VMSCluster system. MSCP$DIS
