Configuring the T1/E1 Interface 79LBO (T1 only) — Line Build Out. The setting for the transmit signal level: 0, 7.5,15, or 22 db. The LBO compensates for the distance between the card and theCSU/repeater. It is a setting for the transmit signal level.Framing — The type of frame organization configured for the T1/E1 portinterface: D4 or ESF for T1. For E1 Framing is a read-only parameter and is alwaysset to multi-frame. Set this parameter to match the service provider or deviceconnection framing.CAUTION: A framing mismatch can cause LOF, OOF alarm conditions and result intraffic loss.Timing (T1 only) — The type of input clock service configured for the T1 module.Set the Timing for T1 UNI ports to System.System — Configures the T1/E1 UNI with IMA interface to use the systemclock as defined in the System Clock Configuration menu as its timing source.For details about designating the system clock, see “Configuring the SystemClock” in Chapter 3.Loop — Configures the T1 module to use the input port Rx clock as the timingsource; timing is received from the service “loop.” This configuration is notrecommended for T1 UNI ports.Gain Limit (T1 only) — The setting for the receive signal level: 26 or 36 dB.AFA — Enables (yes) or disables (no) Automatic Frequency Adjustment. AFAmonitors the error rate detected by the CRC (cyclic redundancy check)error-checking scheme of each of the T1/E1 links (ports). It automatically disablesand re-enables a port when the error rate on that port is at a set level for a settime.Activation Rate — The CRC (cyclic redundancy check) BER (bit error rate) atwhich AFA takes a link out of service based on the Activation Min.: 10 -4, 10 -5,10 -6, 10 -7. For further details about setting this parameter, see“Activation/Deactivation Bit Error Rates” below. This parameter appears onlywhen AFA is enabled.Activation Min. — The period during which AFA monitors the link conditionprior to taking it out of service, in minutes: 15 to 30. This parameter appears onlywhen AFA is enabled.Deactivation Rate — The CRC (cyclic redundancy check) BER (bit error rate) atwhich AFA puts a link in service based on the Deactivation Min.: 10 -4, 10 -5, 10 -6,10 -7. For further details about setting this parameter, see “Activation/DeactivationBit Error Rates” below. This parameter appears only when AFA is enabled.Deactivation Min. — The period during which AFA monitors the link conditionprior to putting it in service, in minutes: 1 to 15. This parameter appears onlywhen AFA is enabled.Admin Status — Administrative status: Out of Service or In Service.Inband Lpbk (T1 only) — Enables or disables inband loopback detection.Activation/Deactivation Bit Error RatesTable 5 translates bit errors rates into the total number of errors for various timeperiods. Use this table as a reference when you are selecting activation anddeactivation bit error rates for the AFA feature.
