Cabletron Systems MMAC-Plus 9E312-12 User Manual

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

Contents

Operation3-2ENIBThe Ethernet Network Interface Block (ENIB) converts Ethernet data packetsreceived through front panel ports into a common canonical format that allowsthe Fast Packet Switching Engine to determine the proper destination port. TheENIB also converts data packets from the common canonical format back toEthernet data packets for transmission out front panel ports.Fast Packet SwitchThe Fast Packet Switch (FPS) is a hardware based switch design that is the keybuilding block of the MMAC-Plus. All filtering/forwarding decisions are made inhardware as opposed to software as in traditional bridges. This custom hardwareallows the FPS to process over 150K frames per second. The FPS is designed tosupport up to 64 ports that are shared between the host processor, the INBbackplane, and LAN/WAN interfaces on the front panel of MMAC-Plusmodules. The FPS can operate in two modes; as a traditional bridge or as aSecureFast Packet Switch (SFPS). When operating in bridge mode, it makesfiltering /forwarding decisions based on Destination Address (DA), withstandard IEEE 802.1d learning. When operating in SFPS mode, allfiltering/forwarding decisions are made based on a DA-SA pair and its receiveport. These DA-SA pairs with the associated receive port are programmed intothe switch using Cabletron’s Automated Connection Management System(ACMS). This provides the network administrator with the ultimate networksecurity without the performance degradation found when using routers orbridges with special filtering capabilities. The MMAC-Plus hub supports modulesoperating in bridge mode and SFPS mode simultaneously providing securitywhen/where needed and ease of configuration where security is not required.i960 HostThe i960 host provides the SNMP protocol stacks, to support industry standardMIBs. Additionally, Cabletron enterprise extension MIBs are supported for eachmedia type. Advanced management services, such as the Distributed LANMonitor, telnet and network address to MAC address mapping, are also providedby the i960 host.The Host engine sends and receives packets via the CPU FPS Interface. Thisallows the bridge to perform spanning tree protocol and other bridging functions.The SMB Interfaces provide communication to the Host Engine for managementfunctions.