NEC NEAX2400 system manual Line Loopback

POST INSTALLATION TEST

Repair Procedure When LED Indicates Abnormality

All 24 B-channels sent from the TSW are looped back to the TSW at Interface on the card. At this time, the adjacent node detects AIS signals. (See ① in the figure below.)

2.Line Loopback

All 24 B-channels sent from the line are looped back to the line at Line Interface on the card. (See ② in the figure below.)

3.Payload Loopback

All 24 B-channels sent from the line are looped back to the line at Speech Path Control Block on the card. (See ➂ in the figure below.)

Self-Node

1 Internal

2

External loopback

3

Payload

Other Node

Loopback

(Line Loopback)

loopback

TDSW Interface

DTI pkg

PAD

Speech Path Control Block

Framer

Line Interface

FUSION

Line Interface

Framer

Speech Path Control Block

PAD

TDSW Interface

Network

front cable

Analysis Method

FCH card

Result of ➀

NG:

Self-Node

has errors

Result of ➀

OK, ➁

NG:

Line has errors

Sending Test

Data Pattern

Result of ➀

OK, ➁

OK: ➂

NG:

Other Node has errors

Figure 6-4 Loopback Points of DTI Card

CHAPTER 6 ND-70185 (E)

Page 136

Revision 3.0