XRT86L30
REV. 1.0.1
SINGLE T1/E1/J1 FRAMER/LIU COMBO
further down the line and its transmission is not being received at the Repeater. Figure 98 below illustrates the
scenario in which the E1 connection from the CO to the Repeater is broken.
FIGURE 98. GENERATION OF YELLOW ALARM BY THE REPEATER UPON DETECTION OF LINE FAILURE
Repeater declares
Red Alarm
internally
Repeater generates
Yellow Alarm to CO
CO
Repeater
CPE
Yellow
Alarm
E1
Transmit
Section
E1
Receive
Section
E1 Receive
Framer Block
E1 Receive
Framer Block
E1
Receive
Section
E1
Transmit
Section
E1 Transmit
Framer Block
E1 Transmit
Framer Block
The E1 line is
broken
The Repeater will also transmit a Blue Alarm, also known as Alarm Indication Signal (AIS) to the CPE. Blue
alarm is an all ones pattern indicating that the equipment is functioning but unable to offer service due to
failures originated from remote side. It is sent such that the equipment downstream will not lose clock
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EXAR [ EXAR CORPORATION ]
