ADTRAN TSU LT Manual do Utilizador descarregar pdf (Página 23)

Chapter 1. Introduction

61202.060L2-1 TSU LT User Manual 11

In addition to the specified self tests, background tests are also run on various

parts of the internal electronics. These run during normal operation to confirm

continued correct functioning. The background tests include:

• Monitoring the phase locked loop for lock

• Standard background network performance monitoring, as required by

ANSI T1.403 and AT&T 54016 for which the results are stored

Loopback Tests

A number of different loopbacks can be invoked locally from the front panel,

by T-Watch commands, or remotely by using special inband codes (AT&T D4

network loop up/loop down codes and V.54 loop up/loop down codes for the

Nx56K/64K serial interface). Additionally the loopbacks can be remotely con-

trolled by out-of-band commands via the T1 ESF facility data link (FDL), or

from T-Watch via a modem connection. Network and DTE interface loop-

backs are discussed in this section.

Network Loopbacks

There are two types of network loopbacks; see Figure 1-7.

Line Loopback

Loops all of the received data back toward the network. The transmitted data

is the identical line code that was received, including any bipolar violations or

framing errors.

Payload Loopback

Similar to line loopback, except that the framing is extracted from the received

data and then regenerated for the transmitted data.

Data Loopback

Loops back all active DS0s and inserts idle code into unoccupied DS0s.

1 2 ... 18 19 20 21 22 23 24 25 26 27 28 ... 76 77

Sem comentários

ADTRAN TSU LT Manual do Utilizador Página 23