Avaya MCC1 Maintenance Procedures page 365

Figure 111: Network Interface at "Dumb" Block with repeater line to Fiber MUX
Figure notes
1 Span Section 1
2 Span Section 2
3 120A2 (or later) Integrated Channel Service Unit
(ICSU)
4 RJ-48 to Network Interface (up to 1000 Feet) (305
m)
Span Section 2 includes the short cable from the loopback jack to the "dumb" block demarcation point
(part of the loopback jack). This is the only portion of section 2 that is part of customer premises wiring
but is not covered in the loopback jack's loopback path.
A problem can exist in one or both of the two sections. The field technician is responsible for finding and
correcting problems in Span Section 1 and the loopback cable portion of Span Section 2. The DS1 service
provider is responsible for finding and correcting problems in the majority of Span Section 2. Testing is
divided into two steps:
1 Test customer premises wiring (section 1 in
page 364) from the ICSU to the loopback jack as described in
2 Test the loopback jack-to-"dumb" block and"dumb" block-to-CO wiring (Span Section 2 in
Figure 110, Network Interface at "Dumb" Block, on page
loopback that "overlaps" the section of the span. Any of the following loopbacks can do this:
a The local ICSU's line loopback, which is typically activated, tested, and then deactivated
by the DS1 service provider at the CO end.
Maintenance Procedures
December 2003
Additional maintenance procedures
DS1 CPE loopback jack (T1 only)
5 Loopback Jack
6 "Dumb" Block (Demarcation
Point)
7 Repeater
8 Fiber MUX
9 Central Office
Figure 110, Network Interface at "Dumb" Block, on
DS1 span test on page
364). This can be done using a
357.
365