ADTRAN 1200291L1, 4200659L1, 4175043L2 STS-1 LOOPBACKS, Line Network, 10. STS-1 Diagnostics Menu

Chapter 6. Diagnostics

STS-1 LOOPBACKS

After you select STS-1 LOOPBACK, the menu in Figure 6-10 appears. The sections following the figure provide descriptions and illustrations of the testing options. Select 1=DATA MODE to end a test in progress.

Figure 6-10. STS-1 Diagnostics Menu

Line Network

LINE NETWORK performs a loop of the STS-1 back to the network. This loopback occurs just prior to the HDB3/B8ZS decoder of the LIU; therefore, any coding violations received by the STS-1 will be inserted back into the network without modification. See Figure 6-11 on page 6-9 for an illustration of this text.

If a LINE NETWORK loopback is active when the MX2800 STS-1 is operating in the FREE-RUNtiming mode, the timing source for the STS-1 is effectively removed from the circuit. Therefore, it is up to the test equipment or network to provide STS-1 timing into the circuit for the duration of the test.

6-8 MX2800 STS-1 User Manual 61200659L1-1