363-206-285
Circuit Pack Descriptions
7-52 Issue 3 June 2001
HDSL Quick Reference Summary 7
Transmission Functions 7
Major transmission functions of the HDSL circuit pack are as follows:
â– Multiplexes four VT1.5 SPEs to a byte-interleaved VT-G signal
â– Provides the VT-G signal to a MXRVO/STS1E circuit pack
â– Inserts VT path overhead
â–
PairGain
compatible, 4-wire HDSL
â– Bi-directional transmission port of 1.544 Mb/s over twisted pair
â– Loopback options
â– Receives up to two HDSL formatted signals
â– Receives a SONET VT-G clock and frame synchronizing signals from its
associated MXRVO/STS1E
â– Demultiplexes the VT-G into four VT1.5 signals
â– Terminates VT path and the embedded DS1 signal from each VT1.5 SPE
â– Desynchronizes the DS1 signals and maps directly into
PairGain
HDSL
â– Provides HDSL to VT1.5 mapping
â– Recovers DS1 clock and NRZ data from each HDSL payload
â– Synchronizes and maps each data signal to a VT1.5 SPE.
Control Functions 7
The major control functions of the HDSL circuit pack are as follows:
â– Protection switching for MXRVO/STS1E circuit packs
â– VT path overhead processing
â– Internal fault detection
â– Inventory information (
CLEI
code, date of manufacture, etc.)
â– Monitors a DS1 signal with SF or ESF frame format and generates PM
data
Maintenance Signal Functions 7
The major maintenance signal functions are as follows:
â– Monitors DS1 signal for near-end and far-end performance
â– Detects VT path AIS
â– Inserts DS1 AIS toward fiber and far-end HDSL equipment