Chapter 6. Diagnostics61200659L1-1 MX2800 STS-1 User Manual 6-3Figure 6-3. Tributary Loopback TestAnalog NetworkAn A NALOG N ETWORK loopback test loops the selected T1/E1 backto the network (STS-1). The T1/E1 is completely de-multiplexed,looped back at the T1/E1 line interface unit (LIU) through the LIUdrivers and receivers, and multiplexed back onto the STS-1network stream. See Figure 6-4 for an illustration of this test.Figure 6-4. Analog Network LoopbackSTS-1MAPPERT1/E1 LIU(1 of 28)T1/E1 LIU(28 of 28)STS-1LIUCODEC(1 of 28)CODEC(28 of 28)STS-1MAPPERT1/E1 LIU(1 of 28)T1/E1 LIU(28 of 28)STS-1LIUCODEC(1 of 28)CODEC(28 of 28)
