DC/DC Converter
DC/DC Converter
The DC/DC converter converts the 48 VDC on the system power bus to the necessary operating voltages for its host network services module. The diagnostic controller monitors and controls the operation of the DC/DC converter.
INB Interface
Each module that attaches to the INB has an INB Network Interface Block (NIB). The INB NIB converts canonical frames to fixed length data blocks for transmission onto the INB. For data blocks received from the INB, the INB NIB reassembles the data blocks received from the INB back into canonical frames for transmission to the Fast Packet Switch (FPS) then from the FPS to the front panel ports.
Fast Packet Switch
The Fast Packet Switch (FPS) is a hardware based switch design that is the key building block of the MMAC-Plus. All filtering/forwarding decisions are made in hardware as opposed to software as in traditional bridges. This custom hardware allows the FPS to process over 150K frames per second. The FPS is designed to support up to 64 ports that are shared between the host processor, the INB backplane, and LAN/WAN interfaces on the front panel of MMAC-Plus modules. The FPS can operate in two modes; as a traditional bridge or as a SecureFast Packet Switch (SFPS). When operating in bridge mode, it makes filtering /forwarding decisions based on Destination Address (DA), with standard IEEE 802.1d learning. When operating in SFPS mode, all filtering/forwarding decisions are made based on a DA-SA pair and its receive port. These DA-SA pairs with the associated receive port are programmed into the switch using Cabletron’s Automated Connection Management System (ACMS). This provides the network administrator with the ultimate network security without the performance degradation found when using routers or bridges with special filtering capabilities. The MMAC-Plus hub can support modules operating in bridge mode and SFPS mode simultaneously providing security when/where needed and ease of configuration where security is not required.
i960 Core
The i960 core provides the SNMP protocol stacks, to support industry standard MIBs. Additionally, Cabletron enterprise extension MIBs are supported for each media type. Advanced management services, such as the Distributed LAN Monitor, telnet and network address to MAC address mapping, are also provided by the i960 core.
3-3
