diff --git a/docs/gsm_agent_install.pdf b/docs/gsm_agent_install.pdf
new file mode 100644
index 0000000..96b0624
Binary files /dev/null and b/docs/gsm_agent_install.pdf differ
diff --git a/src/agent_gsm.py b/src/agent_gsm.py
index bacbe6d..0784645 100644
--- a/src/agent_gsm.py
+++ b/src/agent_gsm.py
@@ -87,15 +87,19 @@ def remove_oldest_log_audio():
 
 
 def detect_degraded_signal(file_test: Path, file_reference: Path) -> SignalBoundaries:
-    global USE_SILENCE_ERASER, LOG_AUDIO, LOG_AUDIO_DIR
+    global USE_SILENCE_ERASER, LOG_AUDIO, LOG_AUDIO_DIR, BackendServer
+
+    is_caller : bool = 'caller' in BackendServer.phone.role
+    is_answerer : bool = 'answer' in BackendServer.phone.role
 
     if utils.get_wav_length(file_test) < utils.get_wav_length(file_reference):
         # Seems some problem with recording, return zero boundaries
         return SignalBoundaries()
     
     r = bt_signal.find_reference_signal(file_test)
-    if r.offset_finish == 0.0:
-        r.offset_finish = 20.0 # Remove possible ring tones in the end of call on my test system
+    
+    if r.offset_start == 0.0 and is_caller:
+        r.offset_start = 5.0 # Skip ringing tones
     return r
 
 
@@ -120,16 +124,20 @@ def run_analyze(file_test: str, file_reference: str, number: str) -> bool:
 
         # Check how long audio file is
         audio_length = utils.get_wav_length(file_test)
-
+        
+        is_caller : bool = 'caller' in BackendServer.phone.role
+        is_answerer : bool = 'answer' in BackendServer.phone.role
+        
+        utils.log(f'Recorded audio call duration: {audio_length}s')
         # Check if audio length is strange - skip such calls. Usually this is missed call.
-        if ('caller' in BackendServer.phone.role and audio_length >= utils_mcon.TIME_LIMIT_CALL) or ('answer' in BackendServer.phone.role and audio_length >= utils_mcon.TIME_LIMIT_CALL * 1.2):
-            utils.log_error(f'Recorded audio call duration: {audio_length}s, skipping analysis')
+        if (is_caller and audio_length >= utils_mcon.TIME_LIMIT_CALL) or (is_answerer and audio_length >= utils_mcon.TIME_LIMIT_CALL * 1.2):
+            utils.log_error(f'Recorded call is too big - looks like mobile operator prompt, skipping analysis')
             return False
         
         try:
             bounds_signal : SignalBoundaries = detect_degraded_signal(Path(file_test), Path(file_reference))
-            bounds_signal.offset_start = 0
-            bounds_signal.offset_finish = 0
+            # bounds_signal.offset_start = 0
+            # bounds_signal.offset_finish = 0
 
             print(f'Found signal bounds: {bounds_signal}')
             # Check if there is a time to remove oldest files
@@ -221,13 +229,12 @@ def make_call(target: str):
 
     # Add prefix and suffix silence for reference to give a chance to record all the file
     reference_filename = '/dev/shm/prepared_reference.wav'
-    utils.prepare_reference_file(fname=REFERENCE_AUDIO, silence_prefix_length=5.0, silence_suffix_length=5.0, output_fname=reference_filename)
+    utils.prepare_reference_file(fname=REFERENCE_AUDIO, silence_prefix_length=10.0, silence_suffix_length=5.0, output_fname=reference_filename)
     
     # Find duration of prepared reference file
     reference_length = int(utils.get_wav_length(reference_filename))
 
     # Compose a command
-    # target = '+380995002747'
     cmd = f'/usr/bin/python3 {DIR_THIS}/bt_call_controller.py --play-file {reference_filename} --record-file {record_file} --timelimit {reference_length} --target {target}'
     retcode = os.system(cmd)
     if retcode != 0:
@@ -247,8 +254,6 @@ def perform_answerer():
     while True:
         # Remove old recording
         record_file = f'/dev/shm/bt_record.wav'
-        # if Path(record_file).exists():
-        #    os.remove(record_file)
 
         cmd = f'/usr/bin/python3 {DIR_THIS}/bt_call_controller.py --play-file {REFERENCE_AUDIO} --record-file {record_file} --timelimit {int(reference_length)}'
         retcode = os.system(cmd)