DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-649DS1-FAC (DS1 Facility)
9
Aux Data 2
indicates that the facility i s detecting a yellow F5 state alarm.
This error only applies to TN1654 DS1 CONV boards in 32-channel E1
operation with CRC enabled via the fib er-link form. The F5 fault state is
defined as a fault in the user-network interface, specific ally in the direction
from the user (PBX) to the network. Refer to CCITT recommendation I.431.
The far-end facility will be in LFA state. To isolate faults for this case, follow
the same repair proced ure as in error type #1025 (Loss of Frame
Alignment) for the other end of the DS1 facility.
h. Alarm Indication Signal (AIS), the BLUE alarm. This alarm ind icates that
the far end of the facility is out of servic e. This means that the other end of
the DS1 facility is undergoing maintenan ce testing or has a LOS condition
and the CSU is providing a Keep Alive si gnal. If the Keep Alive signal is
not supplied b y the CSU, a LOS condition will exist on the facility instead
of the AIS. If a LOS condition exists on the facility, the green LED on the
TN574 DS1 CONV circuit pack that is associated with the facility will be
off; if an AIS condition exists on the facility, the green LED that is
associated with the facili ty that has the AIS will be on. For TN1654 DS1
CONV boards, the LED associated with the fac ility will be lit red if either
the LOS or AIS conditions exist.
To isolate faults for this case, follow the same repair proced ure as in error
type #1793 (Loss of Signal) for the other end o f this DS1 facility.
An RFA alarm indication (YELLOW alarm) is transmitted in response to this
BLUE alarm. If D4 framing is used, transmitted data is corrupted .
i. Loss of Signal (LOS) alarm. This alarm indicates that no sig nal is present
at the DS1 interface associated with the fac ility. On TN574 DS1 CONV
boards, the green LED that is associated with the facility will be off. For
TN1654 DS1 CONV boards, the LED that is associated with the facility will
be lit red. If the LED behavior differs, rep lace the DS1 CONV circuit pack.
Fault isolation for this problem may be different depending on the
capabilities of the CSU devi ce that is being used . Typically, CSUs
provides an LED that is useful for fault isolation (see Figure 9-29). This is
the "16 Zeros" LED. This LED is momentarily lit when a string of 16
consecutive zeros is detec ted in the DS1 signal from the DS1 CONV.
Zeros on a DS1 link are represented by an absenc e of a pulse. Thus, an
active 16 Zeros LED indicates a LOS alarm from the DS1 CONV.
For the following repair proced ure, refer to Figure 9-28 and the diagrams
in the related test descrip tions.
1. If the DS1 facility side LOS indication on CSU A is off (inac tive),
check for a problem b etween the DS1 CONV A circuit pack and the
CPE side of CSU A. Connectors, cables, and the CSU may need to
be replaced.
2. If the DS1 facility side LOS indication on CSU A is on (ac tive),
check for a proble m between the CSU A and the CSU B. Contact
T1 Network Service to resolve the problem. 1