diff --git a/tests/software-upgrades/ONU_Upgrade.robot b/tests/software-upgrades/ONU_Upgrade.robot
new file mode 100755
index 0000000..57a9450
--- /dev/null
+++ b/tests/software-upgrades/ONU_Upgrade.robot
@@ -0,0 +1,123 @@
+# Copyright 2021 - present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# FIXME Can we use the same test against BBSim and Hardware?
+
+*** Settings ***
+Documentation     Tests ONU Software Upgrade
+Suite Setup       Setup Suite
+Test Setup        Setup
+Test Teardown     Teardown
+Suite Teardown    Teardown Suite
+Library           Collections
+Library           String
+Library           OperatingSystem
+Library           XML
+Library           RequestsLibrary
+Library           ../../libraries/DependencyLibrary.py
+Resource          ../../libraries/onos.robot
+Resource          ../../libraries/voltctl.robot
+Resource          ../../libraries/voltha.robot
+Resource          ../../libraries/utils.robot
+Resource          ../../libraries/k8s.robot
+Resource          ../../variables/variables.robot
+
+*** Variables ***
+${POD_NAME}       flex-ocp-cord
+${KUBERNETES_CONF}    ${KUBERNETES_CONFIGS_DIR}/${POD_NAME}.conf
+${KUBERNETES_CONFIGS_DIR}    ~/pod-configs/kubernetes-configs
+#${KUBERNETES_CONFIGS_DIR}    ${KUBERNETES_CONFIGS_DIR}/${POD_NAME}.conf
+${KUBERNETES_YAML}    ${KUBERNETES_CONFIGS_DIR}/${POD_NAME}.yml
+${HELM_CHARTS_DIR}    ~/helm-charts
+${VOLTHA_POD_NUM}    8
+${NAMESPACE}      voltha
+# For below variable value, using deployment name as using grep for
+# parsing radius pod name, we can also use full radius pod name
+${RESTART_POD_NAME}    radius
+${timeout}        60s
+${of_id}          0
+${logical_id}     0
+${has_dataplane}    True
+${teardown_device}    False
+${scripts}        ../../scripts
+
+# Per-test logging on failure is turned off by default; set this variable to enable
+${container_log_dir}    ${None}
+
+${suppressaddsubscriber}    True
+
+# ONU Image to test for Upgrade needs to be passed in the following format:
+${onu_image_name}    ${EMPTY}
+# Example value: twsh.img
+${onu_image_url}    ${EMPTY}
+# Example value: http://bbsim0:50074/images/software-image.img
+${onu_image_version}    ${EMPTY}
+# Example value: v1.0.0
+${onu_image_crc}    ${EMPTY}
+# Example value: 0
+${onu_image_local_dir}    ${EMPTY}
+# Example value: /tmp
+
+*** Test Cases ***
+Test ONU Upgrade
+    [Documentation]    Validates the ONU Upgrade doesn't affect the system functionality
+    ...    Performs the sanity and verifies all the ONUs are authenticated/DHCP/pingable
+    ...    Requirement: Pass image details in following parameters in the robot command
+    ...    onu_image_name, onu_image_url, onu_image_version, onu_image_crc, onu_image_local_dir
+    ...    Check [VOL-3903] for more details
+    [Tags]    functional   ONUUpgrade
+    [Setup]    Start Logging    ONUUpgrade
+    [Teardown]    Run Keywords    Collect Logs
+    ...           AND             Stop Logging    ONUUpgrade
+    ...           AND             Delete All Devices and Verify
+    # Add OLT device
+    Setup
+    # Performing Sanity Test to make sure subscribers are all DHCP and pingable
+    Run Keyword If    ${has_dataplane}    Clean Up Linux
+    Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test
+    FOR    ${I}    IN RANGE    0    ${num_all_onus}
+        ${src}=    Set Variable    ${hosts.src[${I}]}
+        ${dst}=    Set Variable    ${hosts.dst[${I}]}
+        ${onu_device_id}=    Get Device ID From SN    ${src['onu']}
+        Download ONU Device Image    ${onu_device_id}    ${onu_image_name}    ${onu_image_url}    ${onu_image_version}
+        ...    ${onu_image_crc}    ${onu_image_local_dir}
+        # This additional pause to let image download finish on the OLT adapter
+        # as the DOWNLOADED_SUCCEEDED below only indicates that the command is accepted.
+        Run Keyword If    ${has_dataplane}    Sleep    12s
+        ...    ELSE    Sleep    2s
+        Wait Until Keyword Succeeds    ${timeout}    2s    Verify ONU Device Image    ${onu_device_id}
+        ...    DOWNLOAD_SUCCEEDED    IMAGE_UNKNOWN    NO_ERROR
+        Activate ONU Device Image    ${onu_device_id}    ${onu_image_name}    ${onu_image_version}
+        ...    ${onu_image_crc}    ${onu_image_local_dir}
+        # This additional pause to let image download and finish activate on the ONU (BBSim)
+        # as the IMAGE_ACTIVE below is only an indication that the image is accepted for the download to the ONU (BBSim).
+        Run Keyword If    ${has_dataplane}    Sleep    600s
+        ...    ELSE    Sleep    180s
+        Wait Until Keyword Succeeds    ${timeout}    2s    Verify ONU Device Image    ${onu_device_id}
+        ...    DOWNLOAD_SUCCEEDED    IMAGE_ACTIVE    NO_ERROR
+        Wait Until Keyword Succeeds    ${timeout}    5s    Perform Sanity Test     ${suppressaddsubscriber}
+    END
+    # Additional Verification
+    Wait Until Keyword Succeeds    ${timeout}    2s    Delete All Devices and Verify
+    Setup
+    Run Keyword If    ${has_dataplane}    Clean Up Linux
+    Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test
+
+*** Keywords ***
+Setup Suite
+    [Documentation]    Set up the test suite
+    Common Test Suite Setup
+
+Teardown Suite
+    [Documentation]    Tear down steps for the suite
+    Run Keyword If    ${has_dataplane}    Clean Up Linux