Product manual

Product Manual - DM991 Series V Family - 204.4092.08 64
Figure 28. DM991 - LAL Test on E1 Interface
12.3. Digital Interface Tests
12.3.1. LDL Test
This test helps the verification of the internal and external data link status. Two loopbacks are done. The
internal loopback makes the data coming from the G.shdsl interface to be retransmitted. The external
loopback makes the external data coming from the digital interface to return to it. During LDL testing the
data in the digital interface remains in sync with the clocks configured for regular operation. Figure 29
shows the test conditions.
Figure 29. DM991 – LDL on Digital interface
When the modem is configured by
DIPs (DIP B6 = OFF), it is not possible to remotely run tests through
the terminal.