diff --git a/modem/arq_session_irs.py b/modem/arq_session_irs.py
index 231c3cc5..e1be4fad 100644
--- a/modem/arq_session_irs.py
+++ b/modem/arq_session_irs.py
@@ -16,9 +16,6 @@ class IRS_State(Enum):
 
 class ARQSessionIRS(arq_session.ARQSession):
 
-    RETRIES_CONNECT = 3
-    RETRIES_TRANSFER = 3 # we need to increase this
-
     TIMEOUT_CONNECT = 3
     TIMEOUT_DATA = 12
 
diff --git a/modem/arq_session_iss.py b/modem/arq_session_iss.py
index 43f584ba..4c57896f 100644
--- a/modem/arq_session_iss.py
+++ b/modem/arq_session_iss.py
@@ -67,8 +67,7 @@ class ARQSessionISS(arq_session.ARQSession):
             self.log("Timeout!")
             retries = retries - 1
         self.set_state(ISS_State.FAILED)
-        self.log("Session failed")
-        self.event_manager.send_arq_session_finished(True, self.id, self.dxcall, len(self.data), False)
+        self.transmission_failed()
 
     def launch_twr(self, frame_or_burst, timeout, retries, mode):
         twr = threading.Thread(target = self.transmit_wait_and_retry, args=[frame_or_burst, timeout, retries, mode])
@@ -102,11 +101,13 @@ class ARQSessionISS(arq_session.ARQSession):
             self.event_manager.send_arq_session_progress(
                 True, self.id, self.dxcall, self.confirmed_bytes, len(self.data))
 
-        if self.confirmed_bytes == len(self.data) and irs_frame["flag"]["FINAL"]:
-            self.set_state(ISS_State.ENDED)
-            self.log("All data transfered!")
-            self.event_manager.send_arq_session_finished(True, self.id, self.dxcall, len(self.data), irs_frame["flag"]["CHECKSUM"])
-            return
+        if irs_frame["flag"]["FINAL"]:
+            if self.confirmed_bytes == len(self.data) and irs_frame["flag"]["CHECKSUM"]:
+                self.transmission_ended()
+                return
+            else:
+                self.transmission_failed()
+                return
 
         payload_size = self.get_data_payload_size()
         burst = []
@@ -119,3 +120,13 @@ class ARQSessionISS(arq_session.ARQSession):
             burst.append(data_frame)
         self.launch_twr(burst, self.TIMEOUT_TRANSFER, self.RETRIES_CONNECT, mode='auto')
         self.set_state(ISS_State.BURST_SENT)
+
+    def transmission_ended(self):
+        self.set_state(ISS_State.ENDED)
+        self.log("All data transfered!")
+        self.event_manager.send_arq_session_finished(True, self.id, self.dxcall, len(self.data),True)
+
+    def transmission_failed(self):
+        self.set_state(ISS_State.FAILED)
+        self.log("Transmission failed!")
+        self.event_manager.send_arq_session_finished(True, self.id, self.dxcall, len(self.data),False)
\ No newline at end of file
diff --git a/modem/data_frame_factory.py b/modem/data_frame_factory.py
index 96397066..b7583501 100644
--- a/modem/data_frame_factory.py
+++ b/modem/data_frame_factory.py
@@ -124,6 +124,7 @@ class DataFrameFactory:
             "snr": 1,
             "speed_level": 1,
             "frames_per_burst": 1,
+            "flag": 1,
         }
 
         # arq burst frame
@@ -228,12 +229,12 @@ class DataFrameFactory:
 
                 data = int.from_bytes(data, "big")
                 extracted_data[key] = {}
-                if frametype == FR_TYPE.ARQ_BURST_ACK.value:
+                if frametype in [FR_TYPE.ARQ_BURST_ACK.value, FR_TYPE.ARQ_SESSION_INFO_ACK.value]:
                     flag_dict = self.ARQ_FLAGS
-                for flag in flag_dict:
-                    # Update extracted_data with the status of each flag
-                    # get_flag returns True or False based on the bit value at the flag's position
-                    extracted_data[key][flag] = helpers.get_flag(data, flag, flag_dict)
+                    for flag in flag_dict:
+                        # Update extracted_data with the status of each flag
+                        # get_flag returns True or False based on the bit value at the flag's position
+                        extracted_data[key][flag] = helpers.get_flag(data, flag, flag_dict)
             else:
                 extracted_data[key] = data
 
@@ -353,7 +354,11 @@ class DataFrameFactory:
         }
         return self.construct(FR_TYPE.ARQ_SESSION_INFO, payload)
 
-    def build_arq_session_info_ack(self, session_id, total_crc, snr, speed_level, frames_per_burst):
+    def build_arq_session_info_ack(self, session_id, total_crc, snr, speed_level, frames_per_burst, flag_final=False):
+        flag = 0b00000000
+        if flag_final:
+            flag = helpers.set_flag(flag, 'FINAL', True, self.ARQ_FLAGS)
+
         payload = {
             "frame_length": self.LENGTH_SIG0_FRAME,
             "session_id": session_id.to_bytes(1, 'big'),
@@ -361,6 +366,7 @@ class DataFrameFactory:
             "snr": snr.to_bytes(1, 'big'),
             "speed_level": speed_level.to_bytes(1, 'big'),
             "frames_per_burst": frames_per_burst.to_bytes(1, 'big'),
+            "flag": flag.to_bytes(1, 'big'),
         }        
         return self.construct(FR_TYPE.ARQ_SESSION_INFO_ACK, payload)