Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Circuit Pack Descriptions
7-62 Issue 3 June 2001
General Description of Operation 7
The MXRVO circuit pack accepts eight VT-G signals from DS1 circuit packs,
selects seven, combines them to form an STS-1 signal, inserts STS-1 path
overhead, and sends the resulting STS-1 signal to active and standby OLIUs.
The MXRVO selects one of two received STS-1 signals from the OLIUs,
terminates STS-1 path overhead, and demultiplexes the STS-1 into seven VT-G
signals.
The MXRVO interfaces with the OLIU at the STS-1 rate, to eight low-speed DS1
circuit packs at the VT-G rate, and with the SYSCTL circuit pack.
Detailed Description of Operation 7
Transmission Circuitry 7
Transmit Direction. 7
In the transmit direction (from the DS1 low-speed packs), the
VT-G signals from each DS1 are combined into an STS-1 signal (see
Figure 7-24). The STS-1 path overhead and pointer are inserted, and the signal is
transmitted to the OLIU.
Receive Direction. 7
In the receive direction (from the OLIU), the STS-1 path is
terminated. Then, the STS-1 signal is split into seven VT-G signals for
transmission to the DS1 circuit packs.
Control Circuitry 7
The MXRVO circuit pack interfaces with the SYSCTL via the intra-shelf control
bus. The MXRVO provides maintenance elements for reporting the status of the
circuit pack and the incoming STS-1 and VT-G signals, as well as the circuit pack
inventory information (
CLEI code, date of manufacture, etc.). These maintenance
elements are used by the SYSCTL for fault detection and isolation. Conversely,
the MXRVO responds to control signals from the SYSCTL (such as ACTIVE and
FAULT LED controls).