diff --git a/libraries/bbsim.robot b/libraries/bbsim.robot
index 3ba7bd1..ffcad0d 100755
--- a/libraries/bbsim.robot
+++ b/libraries/bbsim.robot
@@ -90,3 +90,11 @@
     @{onuList}=    Split To Lines    ${onus}
     Should Be Equal as Integers    ${rc}    0
     [Return]    ${onuList}
+
+Restart Grpc Server
+    [Documentation]  Restart Grpc Server on a BBSim OLT
+    [Arguments]    ${namespace}    ${bbsim_pod_name}    ${delay}
+    ${res}     ${rc}=    Exec Pod And Return Output And RC    ${namespace}    ${bbsim_pod_name}
+    ...    bbsimctl olt restartServer ${delay}
+    Log     ${res}
+    Should Be Equal as Integers    ${rc}    0
diff --git a/tests/functional/Voltha_FailureScenarios.robot b/tests/functional/Voltha_FailureScenarios.robot
index 4ca307e..4325076 100644
--- a/tests/functional/Voltha_FailureScenarios.robot
+++ b/tests/functional/Voltha_FailureScenarios.robot
@@ -31,6 +31,7 @@
 Resource          ../../libraries/k8s.robot
 Resource          ../../variables/variables.robot
 Resource          ../../libraries/power_switch.robot
+Resource          ../../libraries/bbsim.robot
 
 *** Variables ***
 ${POD_NAME}       flex-ocp-cord
@@ -690,6 +691,29 @@
         ...    Validate Subscriber DHCP Allocation    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}    ${onu_port}
     END
 
+Verify OLT Grpc Disconnection
+    [Documentation]    Restarts OLT Grpc Server and verifies everything works as before without any system disruption.
+    [Tags]    functional    VOL-3904    restartGrpcServer    bbsim
+    [Setup]    Start Logging    restartGrpcServer
+    [Teardown]    Run Keywords    Collect Logs
+    ...           AND             Stop Logging    restartGrpcServer
+    Delete All Devices And Verify
+    Setup
+    Run Keyword If    ${has_dataplane}    Clean Up Linux
+    Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test
+    FOR    ${J}    IN RANGE    0    ${num_olts}
+        ${bbsim_rel}=    Catenate    SEPARATOR=    bbsim    ${J}
+        ${bbsim_pod}=    Get Pod Name By Label    ${NAMESPACE}    release     ${bbsim_rel}
+        Restart Grpc Server    ${NAMESPACE}    ${bbsim_pod}    5
+    END
+    # Repeat sanity test without subscriber changes
+    Wait Until Keyword Succeeds    ${timeout}    2s    Perform Sanity Test    True
+    # 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
+
 Verify ONU Soft Reboot
     [Documentation]    Test soft reboot of the ONU using voltctl command
     [Tags]    VOL-1957    ONUSoftReboot   functional   notready