3Com 3C63311 Reference Guide - Page 186

174 CHAPTER 5: PATHBUILDER S330 DIAGNOSTICS AND PERFORMANCE STATISTICS Table 28 DS1/E1 UNI Module Alarms (continued) Alarm Meaning Troubleshooting Steps Group [n] Multi IMA ID Different group IMA ID Correct link connections and/or IMA received on different links in an group configuration. IMA group. Group [n] Multi Test Different test procedure ATM Forum (R-138) request from different links in an IMA group from the far end. Use the test procedure from the lowest logical link and ignore the other test procedures. Group [n] Multiple Different frame lengths Make sure that the IMA frame length is M received on different links in an set to the same value for all links. IMA group. Group [n] Multiple Symmetry Different group symmetry Configure the group to be symmetric. received on different links in an 3Com PathBuilder products do not IMA group (symmetrical versus support asymmetric bandwidth for asymmetrical operation). IMA. Group [n] Time Sync Fail The far end transmit clocking mode does not match the near end transmit clocking mode Check configuration. Only CTC (Common Transfer Clock) is supported. If the far end transport clocking is set to ITC (Independent Transfer Clock), change it to CTC. IMA Protocol Mismatch IMA label is not ATM Forum 1.0. Near end and far end IMA protocol versions do no match. Check and correct incompatibility. IMA Remote Loopback Far end loopback detected, external cable loopback or crosstalk. Remove loopback condition. IMA Tx The near end IMA networking Misconnected Tx or Rx link state machine ATM Forum (R-123) detects the link is not connected to the correct FE Tx or Rx links. Remove the link and stop Tx and Rx data. Loss of Differential Relative time difference Synchronization between individual T1s/E1s in (LODS) the IMA group is out of range. ATM Forum (R-122) LODS is declared after the Rx IMA fails to synchronize the IMA link(s) in an IMA group within some time limit. Have your carrier verify the time synch and routing of individual T1s/E1s in the group. Check the IMA group configuration to ensure consistency on the local and remote ends. Loss of IMA Frame (LIF) ATM Forum (R-121) Loss of IMA Frame is detected in the Rx direction for an IMA link UP. There is an IMA frame size mismatch between two ends of the circuit. This can be caused by missing ICP cells (ATM cells that carry protocol information), bad IMA ID, bad sequence number, bad M, bad offset HEC error or CRC error in ICP cells. This problem may occur if the link gets noisy and there is no AFA to prevent the ICP from getting corrupted. It is detected in hardware and may or may not cause an operational problem. Check the IMA group configuration to ensure consistent frame size on the local and remote ends. Check links for evidence of noise. Check to be sure that AFA is enabled. (continued)