Several phones in my CUCM8.6 cluster upgraded to updated firmware but failed today. Now I want to find out the root cause and try to fix it. Would anyone tell me how to capture the trace log for phone firmware upgrade? We have dedicated TFTP server and I downloaded the trace log for TFTP service on RTMT, but found nothing associated with the problematic phone's MAC address. Much appreciate if can get some comment from you. Thanks.
Chen
