Nortel Networks manual BayStack 450 Switch LED Descriptions

				BayStack 450 10/100/1000 Series Switches
Table 1-1.	BayStack 450 Switch LED Descriptions (continued)
Label	Type	Color	State	Meaning
		Amber	Blinking	Incompatible software revision or unable to obtain a unit
		or		ID (Renumber Stack Unit table full). The unit is on the ring
		Green		but cannot participate in the stack configuration.
CAS Dwn	Stack mode		Off	The switch is in standalone mode.
		Green	On	The switch is connected to the downstream unit’s
				Cascade A Out connector.
		Amber	On	The Cascade A In connector (CAS Dwn) for this switch is
				looped internally (wrapped to the secondary ring).
		Amber	Blinking	Incompatible software revision or unable to obtain a unit
		or		ID (Renumber Stack Unit table full). The unit is on the ring
		Green		but cannot participate in the stack configuration.
Base	Base mode	Green	On	The switch is configured as the stack base unit.
			Off	The switch is not configured as the stack base unit (or is
				in standalone mode).
			Blinking	Stack configuration error: indicates that multiple base
				units or no base units are configured in the stack.
		Amber	On	This unit is operating as the stack configuration’s
				temporary base unit. This condition occurs automatically
				if the base unit (directly downstream from this unit) fails.
				If this happens, the following events take place:
				• The two units directly upstream and directly
				downstream from the failed unit automatically wrap
				their cascade connectors and indicate this condition
				by lighting their Cas Up and Cas Dwn LEDs (see Cas
				Up and Cas Dwn description in this table).
				• If the temporary base unit fails, the next unit directly
				downstream from this unit becomes the new
				temporary base unit. This process can continue until
				there are only two units left in the stack configuration.
				This automatic failover is a temporary safeguard only. If
				the stack configuration loses power, the temporary base
				unit will not power up as the base unit when power is
				restored. For this reason, you should always assign the
				temporary base unit as the base unit (set the Unit Select
				switch to Base) until the failed unit is repaired or replaced.
				(continued)
302401-D Rev 00				1-7