ETHERNET CHANNELS A, B, C, D, E, and FEMM-E6 User’s Guide1-131.4.2 Ethernet Channels B and CThe Cabletron Systems MultiChannel family of MIMs includes theRepeater Interface Controller Media Interface Module (RIC MIM), anIEEE 802.3 compliant multi-port repeater. You can configure thesemodules to operate on either the Ethernet Channels B or C, or as astandalone repeater, using hardware jumpers or management software.RIC technology provides the option of connecting multiple RIC MIMsover one common bus. This single bus connection allows multiple RICMIMs, communicating over an inter-RIC bus, to act as a single logicalrepeater. For example:• An Ethernet frame follows a path from one RIC MIM, to theinter-RIC bus, to another RIC MIM.• The RIC MIM retimes and regenerates the frame before transmittingit to all ports.Using this configuration yields a path cost equivalent to only one repeaterhop. Since the limit of serially linked repeaters in an Ethernet network isonly four, using the RIC repeater offers a significant advantage. By usingcascading RIC MIMs it is possible to construct a much larger networkthan you could with stand-alone repeaters.Channels B and C traffic travels through RIC MIMs (i.e., TPRMIMs,FORMIMs, and CXRMIMs). These MIMs repeat packets on their own,without the EMM-E6. Ethernet Channels B and C handle network trafficover the RIC management bus on the FNB.When frames have destination addresses for the same bus:• the sending RIC MIM transmits the frames over its designatedEthernet bus;• the other RIC MIMs on this bus receive the frames, and repeat them;• the EMM-E6 receives the frames and, after determining thedestination, filters the frame.
