DEFINITY Enterprise Communications Server Release 7
Maintenance for R7r
555-230-126 Issue 4
June 1999
Additional Maintenance Procedures
6-10DS1 CPE Loopback Jack (T1 Only)
6
DS1 CPE Loopback Jack (T1 Only)
Using the DS1 CPE Loopback Jack (ap paratus code 700A, c omcode
107988867), a technician c an test the DS1 span between the system and the
network interface point. The loopb ack jack is required when DC power appears
at the interface to the ICSU.

The loopback jack is olates the ICSU from the DC

power and properly loops the DC span power

.
NOTE:
The loopback jack op erates with any vintage of TN767E (or later) or
TN464F (or later) DS1 circuit packs and with G3 V3 EDI Release 3 (or later)
software. The loopback jack op erates with the 120A2 (or later) Integrated
Channel Service Unit (ICSU) only;
not
the 31xx series of Channel Service
Units or other external CSUs or earlier ICSUs.

Loopback Jack Installation

Configurations Using a Smart Jack

The preferred location of the loopb ack jack is at the interfac e to the Smart Jack.
This provides maximum coverage of CPE wiring when remote tests are run using
the loopback jac k. If the Smart Jack is not access ible, install the loopbac k jack at
the extended demarc ation point.
1. If there is no extended demarc ation point, install the loopbac k jack directly
at the network interface point as shown in Figure 6-1.
2. If there is an extended demarc ation point and the Smart Jack is not
accessible, install the loopback jac k as shown in Figure 6-2.
3. If there is an extended demarc ation point, but the Smart Jack is
accessible, install the loopback jac k as shown in Figure 6-3.
backup disk 20 Make extra backup c opies of the new files
as needed.
set vector f spe-maint 1 Sets the coredump vector t o take a
coredump when the system reboots.
Restore the system as described above.
Table 6-2. Software Update—Duplicated SPE — Continued
Step Time
(min) Remarks
Continued on next page