Avaya 03-300430 User Manual

Page of 2574
DS1-FAC (DS1 Facility)
Issue 1 June 2005
1073
 
Near-End External Loop-Back Test (#799)
This test is destructive.
This test starts at the DS1 converter circuit pack whose equipment location was entered and 
traverses over the specified facility and loops back at the manually hard-wired external 
loop-back device. Depending on the type of physical connectivity of the DS1 facility, special 
tools, cables or connectors may be required to make the hard-wired loop backs.
To isolate a problem, set the loop back first at the loop-back point LB 1, and then at the 
loop-back point LB 2, see 
on page 1068Place the loop backs at as many points as 
your CSU capabilities will allow. Hard-wired loop backs at the far end are not desirable, because 
the equalization-level adjustments may cause problems.
Every part of this test is executed under firmware control and the result is sent back to the 
maintenance software. The test is executed by sending digital data through every DS1 channel 
on this DS1 facility.
This test is executed via test ds1-facility location external-loopback. It is not 
part of the long test sequence because it requires modifications to the physical connectivity of 
the DS1 facility.
If there is only one DS1 facility available, system will not allow the last facility to be busied out. 
In that case, the DS1 converter circuit pack must be busied out before executing this test.
For a standard-, duplex-, or high-reliability system (no PNC duplication), if there is only one DS1 
facility available, then this test can only be executed at the endpoint that is closer to the media 
server relative to the neighbor DS1 converter circuit pack because of its impacts on the system 
control links. For a critical-reliability system (PNC duplication) or for a system with multiple DS1 
facilities, the test can be executed at any DS1 converter circuit pack.
If the test passes on a TN1654 DS1 facility, the round trip delay time will be displayed in 
milliseconds in the Error Code field. The round trip delay time is defined as the length of time 
in milliseconds it takes for the firmware to receive the test pattern after it has been sent. This 
measurement is taken on the last DS1 channel tested.