Technical data

512 Chapter 18
T1 Analyzer
Making T1 Measurements
T1 Analyzer
Sample Delay Test
Use this test mode to measure the delay between the primary Tx and Rx ports. This
measured delay can be used to determine the approximate distance between near
end and the far end. The far end of the line must be manually looped during this test.
Since a signal is being sent on the T1 line, service on the T1 will be affected.
In this example, you can use this test mode to have the test set measure the round
trip delay of a T1 circuit. It is necessary to have a loop condition at the far end
during this test. The best accuracy is obtained when a hard loop exists at the far end.
The far end CSU can be remotely looped up using the CSU/NIU Loopback mode,
however, be aware that the loopback method in the remote device could add
additional delay. During this mode a pattern consisting of a zero inserted into a
string of ones is transmitted and analyzed to determine the delay in the path. The
selected test pattern is sent as filler during the calculation interval.
Figure 18-6 Delay Connection Diagram