Lucent Technologies FiberReach DDM-2000 User Manual

363-206-305
Technical Specifications
10-60
Issue 3 June 2000
the RT environment. Individual circuit pack failure rates used in the model were
calculated using the method described in TR-TSY-000332, Issue 4,
Reliability
Prediction Procedure for Electronic Equipment (RPP)
. A summary of the circuit
pack failure rates is shown in Table 10-27.
Operation System Interface Availability
10
The Telcordia Technologies objective states that the OS outage should be less
than 28 minutes per year (50 percent hardware, 50 percent software).
*
Therefore,
the objective applies to the TBOS interface
†
. This objective applies to circuitry
needed to maintain communication from the DDM-2000 Multiplexer to the central
office's telemetry equipment for access by an OS. Since the OS interface is used
in the central office, the reliability model assumes the mean time to repair is 2
hours and the environmental factor is 1.0. Table 10-26 lists the predicted outages
for the TBOS interface.
†
Optical Module Maintenance Objective
10
According to Telcordia Technologies, the objective for mean time between failure
(MTBF) of a one-way regenerator is a minimum of four years
‡
. A regenerator is
defined as any circuit pack that performs the electrical-to-optical and optical-to-
electrical conversion. Table 10-27 lists the failure rate and MTBFs of the OLIU
circuit packs. All OLIU circuit packs meet Telcordia Technologies objectives.
Infant Mortality
10
Telcordia Technologies requires that the number of circuit pack failures in the first
year of operation should not exceed 2.5 times the number of failures per year
beyond the first year. The ratio of first year failures to failures in subsequent years
is known as the infant mortality factor (IMF). The requirement is to have an IMF of
less than 2.5.
§
DDM-2000 FiberReach Multiplexer circuit packs are subjected to an
environmental stress-testing (EST) program. The purpose of the program is to
eliminate early life failures, conduct failure mode analysis on defective circuit
packs, and use corrective action to make the product more reliable. All new circuit
pack codes in manufacturing are subjected to EST. However, based on field return
data, when the early life failures for any circuit pack codes have been minimal and
the IMF is below 2.5, these circuit pack codes may be subjected only to sampling
EST.
* TA-NWT-000418, Issue 3, November 1991, p. 36.
† Not applicable for Release 3.0 and later.
‡ TA-NWT-000418, Issue 3, November 1991, p. 37.
§ TA-NWT-000418, Issue 3, November 1991, p. 40.

Lucent Technologies FiberReach DDM-2000 Specifications

General

Brand	Lucent Technologies
Model	FiberReach DDM-2000
Category	Multiplexer
Language	English