CTC Union TRM01, User Manual

Page: 27 / 48

Chapter 4. Loop Back Testing
23
TRM-01 APR 2000
4.1 General
In this chapter we shall explain the detailed functioning of the loop back
switches.
4.2 User Activated Loop back
The
FT1 Card supports the following types of test loop backs.
Data Port local analog loop back.
T1 link local digital loop back.
T1 link remote loop back. (only works in CAS or CCS frame mode)
The user activated loop back functions may be accessed from the front
panel FT1 Card push-button switches, via the LOOPBACK PARAMETER
menu under ASCII terminal mode, or via SNMP. The latter two methods both
require the optional
SNMP Card installed and will not be discussed any further
here. The available test functions via pushbutton switches are described on this
and the following pages.
4.3 T1 link local digital loop back
The FT1 Card local digital loop back is established as close to the DTE
interface as possible to check the satisfactory working of the FT1 Card and the
T1 link connection. Using this setting, the remote CSU/DSU must supply the
test signal and verify it upon its return.
(
Loc dig loopbk depressed)
Figure 4-1. T1 link local digital loop back
User
DTE
Data
Port
T1
CSU
LOCAL FT1 Card