Cabling The Metallic Loop Test Access Ports; Mlt-Port Cabling For Line Tests; Figure 4-12 Metallic Loop Test Ports; Table 4-6 Mlt In And Mlt Out Pin Assignments - Hatteras HN4000 Hardware Installation Manual

4.7

Cabling the Metallic Loop Test Access Ports

The HN4000 provides external test access to 2BASE‐TL copper loops via two Metallic Loop
Test (MLT) RJ‐45 jacks labeled "OUT" and "IN" (Figure
Technicians can use the MLT to pre‐qualify copper‐loops prior to turn‐up. A key benefit of
using the HN4000 switch's MLT port is that it ensures end‐to‐end connectivity from the switch
to the attached CPE device. Refer to the HN4000 User Guide for more information about copper‐
pair testing with the MLT.

4.7.1 MLT-Port Cabling for Line Tests

The HN4000 switch has an internal test bus that provides configurable connections between a
2BASE‐TL PME and the MLT test ports (Figure

Figure 4-12 Metallic Loop Test Ports

Table 4‐6 shows the MLT ports' pin assignments (which apply to both the "IN" and "OUT"
ports).
Table 4-6 MLT IN and MLT OUT Pin Assignments
Pin Position
4
5
By using a line‐test's config command, you specify which PME to connect to the switch's MLT
"IN" test port. For example, the command config mlt set 2bpme 3/21 connects PME 21 on
switch 3 to the switch's MLT "IN" port.
When switches are in a stack, you can connect the "IN" MLT to the "OUT" port of another
switch to chain the MLT ports together (as described in the following section).
920550-5020 Rev 14
Signal
Tip
Ring
Cabling the Metallic Loop Test Access Ports
4‐12)
4‐12).
HN4000 Hardware Installation Guide
4-17