Call failure is due to poor signal condition.
You can see that SNR was very poor , SACCH CRC keeps failing and finally radio link failure happens and call drop
// Call setup
07:45:19.683 cnmlog.c 784 H ds2=MNCNM= CNM msg info:PD_CC, msg_type=SETUP
07:45:19.690 cnmlog.c 760 H ds2=MNCNM= CNM msg info:PD_CC, msg_type=CALL_CONFIRMED
07:45:20.570 cnmlog.c 756 H ds2=MNCNM= CNM msg info:PD_CC, msg_type=ALERTING
07:45:23.586 cnmlog.c 768 H ds2=MNCNM= CNM msg info:PD_CC, msg_type=CONNECT
07:45:24.769 cnmlog.c 772 H ds2=MNCNM= CNM msg info:PD_CC, msg_type=CONNECT_ACK
// SACCH CRC keeps failing
07:45:24.914 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:25.874 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:27.314 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:27.794 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:28.275 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:55.634 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:56.114 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
07:45:56.594 l2_send.c 306 H SACCH CRC failure: L1 buffer reset, treat SRO as 0
// SNR gets very poor
Time FN Chan name Chan# Arfcn Rssi Power (dBm) Gain Snr (dB)
07:45:24.914 481558 SACCH 4 664 130813 -93.13 1 3.54
07:45:24.914 481584 SACCH 4 664 19939 -101.31 1 3.79
07:45:24.914 481610 SACCH 4 664 114973 -93.69 1 9.25
07:45:24.914 481636 SACCH 4 664 185420 -91.63 1 4.73
07:45:45.076 485926 SACCH 4 664 107363 -93.94 1 1.55
07:45:45.076 485952 SACCH 4 664 65468 -96.13 1 1.63
07:45:45.076 485978 SACCH 4 664 194600 -91.38 1 0.10
07:45:45.076 486004 SACCH 4 664 9885 -104.31 1 -0.78
07:45:45.556 486030 SACCH 4 664 54903 -96.88 1 1.33
07:45:45.556 486056 SACCH 4 664 19158 -101.44 1 -0.86
07:45:45.556 486082 SACCH 4 664 28821 -99.69 1 0.25
07:45:45.556 486108 SACCH 4 664 126024 -93.25 1 0.26
// Radio link failure and call drop
07:45:56.594 rr_control.c 15147 H gs2:RadioLinkFailure EV in Dedicated
07:45:56.595 rfgsm_cmd_processing.c 1612 H |tsk:2|RF GSM Cmd Proc Rx Burst prx_dev=0 num bursts=1
07:45:56.596 rr_conn_release.c 1553 H gs2:Release Link (RLF)
I don’t see UE side issue. It’s due to poor signal conditions.