Cabletron Systems MMAC-Plus 9E312-12 User Manual

Also see for MMAC-Plus 9E312-12: Appendix

Contents

3-3INB NIBINB NIBEach module that attaches to the Internal Network Bus (INB ) has an INBNetwork Interface Block (NIB). The INB NIB converts canonical frames to fixedlength data blocks for transmission onto the INB. For data blocks received fromthe INB, the INB NIB reassembles the data blocks received from the INB back intocanonical frames for transmission to the Fast Packet Switch (FPS) then from theFPS to the front panel ports.System Management BusesThere are two management channels within the MMAC-Plus system: the SMB-1and the SMB-10. These buses provide out-of-band management and inter-modulemanagement communication.SMB-1 BusThe SMB-1 is a 1Mbs management bus located within the MMAC-Plus. This busis utilized by all diagnostic controllers in the system including connectivitymodules, power supply modules and the environmental module. The SMB-1transports inter-chassis information between system components, such as powerand environmental information, as well as diagnostic messages. Periodicloop-back tests are performed by all modules which share this bus to ensure thevalidity of SMB-1. In the event a failure is detected on SMB-1, the SMB-10 may beused as an alternate communication channel.SMB-10 BusThe SMB-10 is a 10Mbs management bus located within the MMAC-Plus. Thisbus is used for inter-chassis communication of modules as well as serving as anout-of-band management channel into the MMAC-Plus. The SMB-10 isexternalized from the chassis via an optional Ethernet Port Interface Module(EPIM) located on the front of the Environmental Module. Through an EPIMconnection, full SNMP management of the MMAC-Plus is available out-of-bandfrom user data. Modules which share the SMB-10 bus periodically send out loop-back packets to ensure the validity of SMB-10. If a fault is detected on the SMB-10,the SMB-1 is used by the modules as an alternate communication channel.System Diagnostic ControllerThis diagnostic controller is composed of a Z-80 microprocessor and itssupporting logic. The diagnostic controller is designed to control the power-upsequencing of modules, monitor the 9E312-12 input and output powerparameters, keep watch over the main host processor, monitor the temperature,