Chapter 3 System Features
PSAX System Software Features
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PSAX 2300 Multiservice Media Gateway User Guide
, Issue 1
Release 9.0.0
ment (CPE) products at the edge of an ATM network. The PSAX system also
generates alarm indication signals on all affected DS1 connections whenever
a loop is activated.
DS0A Non-Latched Loop Codes
In addition to the no loopback and the line loopback modes of operation
present in the 12-Port Medium-Density DS1/E1/DS0A module (DS0A mode)
in Release 7.1.3, three new, user-configurable, loopback modes have been
added in Release 8.0.0:
•
Transmit mode
•
Monitor mode
•
Transmit and monitor mode
In conjunction with these three modes, six fields can be configured:
•
Transmit loop up code
•
Transmit loop down code
•
Receive loop up code
•
Receive loop down code
•
BERT pattern
•
Timeout (Transmit loop code duration)
In Transmit mode, the module outputs 1 second of transmit loop up code fol-
lowed by 1 second of BERT pattern on the line, repeating this pattern until
Timeout is reached, at which point 1 second of transmit loop down code is
sent on the line. The module is also in remote loopback in this mode. The
purpose of this mode is to test the operation of the module connected on the
far end of the line when it detects and returns the loopcodes transmitted. The
DS0A module reports to the CPUn module whether the transmit loop up
code or transmit loop down code was received.
Monitor mode is the opposite of transmit mode. Here, the module on the far
end must verify that the near-end DS0A module is working properly by
sending loop codes on the line. In monitor mode, the DS0A module operates
normally—that is, passes real traffic—until it receives the receive loop up
code on the line. At that point, the module is set to line loopback and remote
loopback and reports to the CPUn module that it had a matching of the
receive loop up code. When the DS0A module detects the receive loop down
code, it is taken out of loopback and reports the receive loop down code
matching to the CPUn module. If the module is in loopback mode and does
not detect either of the receive loop codes, it automatically returns to normal
mode after two minutes.
Transmit and monitor mode is exactly the same as transmit mode except that
the DS0A module also reports to the CPUn module a matching of the receive
loop up and loop down codes.
