DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Maintenance Object Repair Procedures
9-565DS1-BD (DS1 Interface Circuit Pack)
9
The TN767E circuit pack combined with Lucent’s new 120A1 CSU Module forms
an Enhanced Integrated CSU. The new 120A1 CSU Module, when c ombined
with the functionality provided by the TN767E hardware and firmware, and new
switch software, provides func tionality equivalent to an external stand -alone
Lucent ESF T1 CSU. The 120A1 CSU Module connects to the TN767E circu it
pack on the I/O connec tor panel on the back of the p ort carrier. The new CSU
Module, thus becomes an inte grated part of the DEFINITY. system. Throughout
the document, the term 120A1 will mean a 120A1 or later suffix CSU Module.
The Enhanced Integrated CSU is for use in the United States of Americ a with
1.544 Mbps DS1 service. For further details on the 120A1 CSU Module see
DEFINITY. Communications System Generic 1, Generic 2, and Generic 3 V1 and V2 - Integrated CSU Module Installation and Op eration, 555-230-193.
The TN767E and 120A1 CSU Module support on-demand loopback tests that
assist in the detection of faults b etween the TN767E circuit pack and the CSU
Module, between the Integrate d CSU and the optional Customer Premises
Loopback Jack , or between the Integrated CSU and remote CSU. These
loopback tests are exp lained in detail later in this DS1-BD sectio n, but Figu re
9-26 gives a high level overview of the loop back points.
The following list of acronym definition s are for Figure 9-26:
■PLB = Payload Loopbac k
■BLB = Board Loopback
■ELB = Equipment Loopb ack
■LLB = Line Loopbac k
■RLB = Repeater Loopbac k
■CLJ = Loopback Jack Loopback
■R-LLB = Remote Line Loopback
■SMRT = Sma rt Jac k
■LPBK = Loopback
For more information about DS1 interfaces, see the
DEFINITY Communications System DS1/CEPT1/ISDN-PRI Reference
, 555-025-107.