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Circuit Pack Descriptions
7-32 Issue 3 June 2001
Figure 7-11. BBF1/BBF1B DS1 Option Switches
DS1 Quick Reference Summary 7
Transmit Functions 7
Major transmit functions of the DS1 circuit pack are as follows:
■ Receives four AMI or B8ZS encoded DS1 signals from a DSX-1
■ Recovers DS1 clock and NRZ data from each DS1 signal
■ Synchronizes and maps each data signal to a VT1.5 synchronous payload
envelope (SPE)
■ Inserts VT path overhead
■ Multiplexes four VT1.5 SPEs to a byte-interleaved VT-G signal
■ Provides the VT-G signal to a MXRVO/STS1E circuit pack.
Receive Functions 7
Major receive functions of the DS1 circuit pack are as follows:
■ Receives a SONET VT-G clock and frame synchronizing signals from its
associated MXRVO/STS1E
■ Demultiplexes the VT-G into four VT1.5 signals
■ Terminates VT path and the embedded DS1 signal from each VT1.5 SPE
■ Desynchronizes the DS1 signals
■ Encodes each DS1 signal into either AMI or B8ZS format
■ Pre-equalizes (with LBO) each DS1 and provides them to a DSX-1 as
bipolar signals.
DS1LineCodeSettings
Line Code Format
(Note 2)
DIP Switch Settings (Note 1)
S1-4
(Port 1)
S1-5
(Port 2)
S1-6
(Port 3)
S1-7
(Port 4)
B8ZS OFFOFFOFFOFF
AMI ON ON ON ON
Notes:
1. Switch section 8 (S1-8) is unused and ignored by the system.
2. Line code is software overrideable.