Cabletron Systems EMM-E6 Ethernet manual Ethernet Channels B and C

ETHERNET CHANNELS A, B, C, D, E, and F

1.4.2Ethernet Channels B and C

The Cabletron Systems MultiChannel family of MIMs includes the Repeater Interface Controller Media Interface Module (RIC MIM), an IEEE 802.3 compliant multi-port repeater. You can configure these modules to operate on either the Ethernet Channels B or C, or as a standalone repeater, using hardware jumpers or management software.

RIC technology provides the option of connecting multiple RIC MIMs over one common bus. This single bus connection allows multiple RIC MIMs, communicating over an inter-RIC bus, to act as a single logical repeater. For example:

•An Ethernet frame follows a path from one RIC MIM, to the inter-RIC bus, to another RIC MIM.

•The RIC MIM retimes and regenerates the frame before transmitting it to all ports.

Using this configuration yields a path cost equivalent to only one repeater hop. Since the limit of serially linked repeaters in an Ethernet network is only four, using the RIC repeater offers a significant advantage. By using cascading RIC MIMs it is possible to construct a much larger network than 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 traffic over 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 designated Ethernet bus;

•the other RIC MIMs on this bus receive the frames, and repeat them;

•the EMM-E6 receives the frames and, after determining the destination, filters the frame.

EMM-E6 User’s Guide 1-13