When I run sipp in background mode it doesn't detect any incoming messages. When I ran with the same parameters just without the -bg, it does. I have a sip client which I run exactly the same sending a register request to sipp.
Normal run:
sipp -sf $SIPP_SCENARIOS_PATH/uas-auth.xml -p 9000 -m 1 -t t1 -key test_folder $SIPP_TEST_PATH -trace_msg -message_file $SIPP_TEST_PATH/messages.log -trace_logs -log_file $SIPP_TEST_PATH/sipp_log.log -trace_err -error_file $SIPP_TEST_PATH/sipp_error_log.log
Background run:
sipp -sf $SIPP_SCENARIOS_PATH/uas-auth.xml -bg -p 9000 -t t1 -m 1 -key test_folder $SIPP_TEST_PATH -trace_msg -message_file $SIPP_TEST_PATH/messages.log -trace_logs -log_file $SIPP_TEST_PATH/sipp_log.log -trace_err -error_file $SIPP_TEST_PATH/sipp_error_log.log