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Technical Specifications
10-2
Issue 1
December 1997
Electrical Interfaces
1
0
The DDM-2000 OC-12 Multiplexer supports DS3 and EC-1 electrical low-speed
interfaces.
DS3 Low-Speed (BBG11/11B 3DS3)
1
0
■
Electrical Specification
The low-speed DS3 interface transmits/receives a standard electrical DS3
signal as specified in
ANSI T1.102-1993, Section 5 (44.736 Mb/s rate,
DSX-3 interconnect specification, bipolar 3-zero substitution [B3ZS]
encoding). However, the signal does not have to contain a standard DS3
frame.
Line build-out is provisionable as follows:
— 734A/D: Up to 450 ft.
— Mini-Coax (KS-19224, L2): 0 to 150 ft.
— 735A: Up to 250 ft.
■
Format Specification
The DS3 low-speed interface provides clear channel (CC) transport of any
DSX-3 compatible signal (M13 mode, framed CC, unframed CC). Thus,
there are no format requirements on this interface.
■
Alarm Thresholding
The following parameters are monitored at the DS3 interface to the DSX-3:
— Loss of signal (LOS)
— Line coding violations (CV-L).
The alarm level for each of the monitored parameters can be provisioned to
CR, MJ, MN or status. B3ZS coding violation failure threshold is user
settable to 10
-3
or 10
-6
BER.
■
Performance Monitoring (PM) (see Table 10-14)
— DS3 Parity Errors (P-bits)
DDM-2000 OC-12 Multiplexers provide for DS3 P-bit violation
monitoring and removal (VMR) based on the provisioning mode of
the DS3 low-speed interface. Table 10-2 defines P-bit monitoring
and correction actions in each of the DS3 modes.
— Severely Errored Frame Seconds (SEFS)
DDM-2000 OC-12 Multiplexers count the number of seconds during
which an out-of-frame (OOF) condition exists for DS3 signals
received from the fiber.