Optical Bypass Switch; Led Power-Up Sequence - Cabletron Systems 3F00-01 User Manual

Chapter 2: Connecting to the Network

2.1.4 Optical Bypass Switch

An Optical Bypass Switch (OBS) may be used to provide added
protection when the ATX is configured as a DAS. If an OBS is connected
to the 3F00-01 or 3F55-01, and a failure occurs at the ATX, the OBS
automatically isolates the ATX from the rest of the network by
reconfiguring the FDDI dual rings as shown in Figure 2-4.
ATX ATX
3F00-01 3F00-01
OBS OBS
Through Mode Bypass Mode
(Normal)
Figure 2-4 Optical Bypass Switch Operation
This avoids ring "wrapping" (automatic reconfiguration to isolate a fault)
and ring re-initialization. In addition, an OBS makes it possible to
disconnect the ATX from the network without disrupting the FDDI rings.

2.2 LED POWER-UP SEQUENCE

Before connecting the 3F00-01 or 3F55-01 to the network, power on the
ATX and observe the automatic power-up diagnostics sequence of the
front panel LEDs to check for proper operation. Refer to the ATX User
Guide for instructions on how to power up the ATX.
Each of the modules in the ATX is tested in order, (from top to bottom of
the unit). The power-up sequence takes between 1 and 2 minutes,
depending on the ATX configuration.
FDDI Dual-Attached Intelligent Module User's Guide Page 2-5