Using Loopback Tests 225G.826 Far End To view E1 Span far end statistics:1 Log in to the NBX NetSet utility using the administrator username andpassword.2 In the Select Device Type box, select ISDN PRI Span List and then clickApply.3 When the Span List appears, click a span and then click G.826 Far End toopen the G.826 Far End Performance screen.4 Click the Help button for details about each dialog box field.Using LoopbackTestsThe 3C10116D T1 and 3C10165D E1 cards can respond to commandsfrom the Central Office to loop back data at different points fordiagnostic purposes.You enable each loopback test using the NBX NetSet utility. You initiatethe Local and Framer loopback tests using the NBX NetSet utility. The Lineand Payload loopback tests must be initiated by the Central Office or bytest equipment emulating Central Office equipment.For detailed logging information, you can enable TEP logging before youenable loopback testing. However, setting up logging and interpretingthe logs are advanced tasks that require help from a support technician.You can see a simple pass/fail result by viewing the span status, asdescribed in “Enabling or Disabling Loopback Tests” on page 226. To seethe loopback test status of all spans, use the Config & Status Reportbutton on the Device Configuration > Digital Line Cards tab of the NBXNetSet utility.The cards loop back data at the following points and with the followingcharacteristics:■ Line Loopback — A loopback in which the signal returned towardthe source of the loopback command comprises the full 1.544 Mbits/ssignal with bit sequence integrity maintained, no change in framing,and no removal of bipolar violations.■ Local Loopback: An internal (within the framer) diagnostic loopbackin which the signal returned towards the source is framed.■ Framer Loopback — An internal (within the framer) loopback thattests the path up to where framing is introduced.
