AT&T DS1/DMi/ISDN-PRI manual Figure B-15.Synchronization from Dacs Node

SAMPLE INSTALLATION AND MAINTENANCE PROBLEMS B-13

for System 85s that are configured with the ANN11C version 8 or later circuit pack. Figure B-15, Synchronization from DACS Node, shows a configuration that obtains synchronization from a DACS.

DS1 OR DMI		DACS
INTERFACE	PRIMARY REFERENCE
		(STRATUM 3)
LOCATION A		OR BETTER

DS1 OR DMI
INTERFACE	PRIMARY	REFERENCE
LOCATION B
	PRIMARY	REFERENCE
OTHERS

Figure B-15.Synchronization from DACS Node

TYPICAL PHYSICAL INTERFACE CONNECTION PROBLEMS

The physical interface from a DS1/DMI circuit pack carrier-cabinet to the transmission facility (such as the type of cable and cable group numbers) is primarily determined by:

●Version of the switch and vintage of the circuit pack

●Type of transmission facility (such as on-premises, off-premises, metallic, or nonmetallic)

●Any optional transmission products that might be in the circuit

Initially and for the first several System 85s that provided DS1 service, all DS1 connections were engineered using special shielded cable (type DCC-5/24-TSA cable). This arrangement was incompatible with the premises distribution system (PDS) and also presented problems for supporting DMI connections to compatible computers. There were other incompatibilities between various products in terms of connectors and connector pin assignments.