Cabletron Systems SmartSwitch SBU128 User Manual

Cabletron Systems SmartSwitch SBU128 User Manual Manual pdf 24 page image

Front and Rear Panel Descriptions80-10200000-01 3–53.1.4 ISDN IndicatorsThese indicate the state of channels 1 and 2 on the ISDN and are:-Indicator Channel stateLAYER 1 Alight when the ISDN at Layer 1 (physical layer) isactive. When not alight when dialling indicates lack ofconnection to the ISDN.LAYER 2 Alight when the ISDN at Layer 2 (link layer, LAPD) isactive. This must be alight for calls to be made. If notalight check firstly the ISDN connection, then trydialling again. If still not alight check with your networkprovider.B1 IN USE Lights to indicate B channel 1 on the ISDN is in use (iscarrying a call).B2 IN USE Lights to indicate B channel 2 on the ISDN is in use (iscarrying a call).CONNECTED Lights to indicate that the User port is connected to theISDN in backup, and data is passing over the ISDN Bchannel.3.1.5 Status IndicatorWhen powering up, the STATUS LED is on solid for several secondswhile the unit loads its operational software. When loaded, the STATUSLED will flash slowly indicating unit operational status.3.1.6 Power IndicatorThis indicates the presence of internal DC power. This indicator shouldalways be lit when mains power is connected.Note that if the SBU128 is not powered up, the internal pass throughrelays will connect the USER port to the LINK port. This will allownormal operation of the user’s equipment, although the ISDN backup willnot function.