Chapter 3. Operation61200.129L1-1 TSU 120 User Manual 8 5REMOTE LOOPBCKThis activates the same loopbacks as Local Loopbackbut at the far end. It uses either the in-band loop-upcode as specified by ANSI T1.403 for line loopback(ATT In-Band LLB), or the FDL as specified in ANSIT1.403 for payload and line loopback codes. Thefollowing options are available:ATT In-Band LLB Activates the line loopbackusing inband codeANSI FDL LLB Initiates the transmission ofan FDL payload loop-up codetoward the far endANSI FDL LLB Initiates the transmission ofan FDL line loop-up codetoward the far endNo Loopback Deactivates the loopbackRemote Loopback cannot be used with Fractional T1 sincethe full T1 stream including the FDL is not transported tothe far end.Scroll to select a setting and record it by pressingEnter. The unit returns the cursor to 2)LOCALLOOPBCK.Scroll to select 1)Local Loopback or 3)Pattern.After a Remote Loopback option is selected, the TSU120 verifies that the far end is actually in a loopbackby checking for the receipt of a code looped back fromthe far end. Once the Remote Loopback type isselected, the LCD displays the loopback progress bydisplaying Looping until loopback is verified.
