EMM-E6 Ethernet User's Guide

CHAPTER 1: INTRODUCTION
1-16 EMM-E6 User’s Guide
Only one EPIM operates at any given time. However, using both EPIM
slots in a redundancy configuration ensures that if the primary bridging
port fails, or the connecting cable segment becomes inoperable, the backup
port automatically takes over the bridging operation. This is referred to as
Front Panel Redundancy.
As it does for Channels B and C, the EMM-E6 only bridges (i.e., it does
not repeat) Channel D traffic. When the EMM-E6 receives a frame
destined for Channel D, it goes through the normal bridging process for
that frame and filters/forwards the information accordingly.
1.5 CHANNELS E AND F
The EMM-E6 provides interfaces for two optional Bridge Router
Interface Modules (BRIMs). These modules provide the EMM-E6 with
additional connectivity for either bridging or routing functions. At the
same time, BRIMs provide access to various transmission methods.
As bridging modules, BRIMs perform the same functions as EPIMs; they
transfer packets between different channels. However, unlike EPIMs,
BRIMs bridge these packets from one transmission type to another (e.g.,
Ethernet to FDDI).
CH1Book Page 16 Wednesday, March 20, 1996 7:48 AM