363-206-305 Detailed Level Procedures:
Issue 3, June 2000 Page 1 of 2
DDM-2000 F
IBER
R
EACH
N
ARROWBAND
S
HELF
DLP-511
Perform DDM-
-
2000 NBS
MLT Channel Test
Summary:
Channel testing for NBS circuits is supported by MLT using a DC test pair connected
to the RT via PairGain test controller (PGTC), test bus control unit (TBCU), or a
derived DC test PairGain provided by a remote measurement unit (RMU) capable of
returning a DC delta signature provided by the DT Server at the RT. The extended
test controller (XTC) is supported only when connected in the PGTC emulation mode
and the special features of the XTC are unavailable.
Channel testing for the NBS circuits in an integrated
SLC
-2000 Access System is
supported by MLT but not XTC or PGTC. The test bus control unit (TBCU) connects
the DC test pair or RMU to perform the bypass test as previously mentioned.
When a channel test is performed, the MLT identifies the circuit as being served by a
SLC
Carrier System. Then two tests are initiated. The first test performs channel unit
functional tests, and the second test bypasses the carrier system [using a DC test
pair or remote measurement unit (RMU)] and returns a DC delta signature from the
DT Server that indicates the result of the attempted channel tests performed by the
CDTU at the NBS.
MLT has no means of obtaining metallic access to the copper drop which connects to
the NBS. This situation is handled by having the CDTU in the NBS measure the
characteristics of the copper drop, then reporting the results using DC programmable
signatures. When a test is run, the DT Server at the RT returns a DC signature (Table
A) to the MLT. A DC signature with 44K ohms or less Tip-to-Ring indicates a good
HDT to NBS facility. A DC signature of 1000K ohms or more Tip-to-Ring indicates a
failure condition associated with the HDT to NBS facility; trouble clearing should
begin at the HDT site. A DC signature of less than 24K ohms may indicate a trouble
condition at the NBS or customer equipment/wiring. A failed DC signature indicates
the RT unit has failed or the signal between the RT and NBS is bad.
To Next Page
Loading...