[VOL-4041] Migration to single ONOS SSH connection

Change-Id: I91f5f3c96585097486bc862118d8753bf4b30cba
diff --git a/tests/tt-workflow/Voltha_TT_FailureScenarios.robot b/tests/tt-workflow/Voltha_TT_FailureScenarios.robot
index 02a56a0..563ac0e 100755
--- a/tests/tt-workflow/Voltha_TT_FailureScenarios.robot
+++ b/tests/tt-workflow/Voltha_TT_FailureScenarios.robot
@@ -91,7 +91,7 @@
         ...    Check Ping    False    ${dst['dp_iface_ip_qinq']}    ${src['dp_iface_name']}
         ...    ${src['ip']}    ${src['user']}    ${src['pass']}    ${src['container_type']}    ${src['container_name']}
         # Remove Subscriber Access (To replicate TT workflow)
-        Wait Until Keyword Succeeds    ${timeout}    2s    Execute ONOS CLI Command    ${ONOS_SSH_IP}
+        Wait Until Keyword Succeeds    ${timeout}    2s    Execute ONOS CLI Command use single connection    ${ONOS_SSH_IP}
         ...    ${ONOS_SSH_PORT}    volt-remove-subscriber-access ${of_id} ${onu_port}
         Sleep    5s
         # Enable Power Switch
@@ -100,7 +100,7 @@
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds   120s   2s
         ...    Verify ONU Port Is Enabled   ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}    ${src['onu']}
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds    ${timeout}    2
-        ...    Execute ONOS CLI Command    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}
+        ...    Execute ONOS CLI Command use single connection    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}
         ...    volt-add-subscriber-access ${of_id} ${onu_port}
         # Verify ONU state in voltha
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds    360s    5s    Validate Device
@@ -194,13 +194,13 @@
         ...    Check Ping    False    ${dst['dp_iface_ip_qinq']}    ${src['dp_iface_name']}
         ...    ${src['ip']}    ${src['user']}    ${src['pass']}    ${src['container_type']}    ${src['container_name']}
         # Remove Subscriber Access (To replicate TT workflow)
-        Wait Until Keyword Succeeds    ${timeout}    2s    Execute ONOS CLI Command    ${ONOS_SSH_IP}
+        Wait Until Keyword Succeeds    ${timeout}    2s    Execute ONOS CLI Command use single connection    ${ONOS_SSH_IP}
         ...    ${ONOS_SSH_PORT}    volt-remove-subscriber-access ${of_id} ${onu_port}
         # Check ONU port is Enabled in ONOS
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds   120s   2s
         ...    Verify ONU Port Is Enabled   ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}    ${src['onu']}
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds    ${timeout}    2
-        ...    Execute ONOS CLI Command    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}
+        ...    Execute ONOS CLI Command use single connection    ${ONOS_SSH_IP}    ${ONOS_SSH_PORT}
         ...    volt-add-subscriber-access ${of_id} ${onu_port}
         # Verify ONU state in voltha
         Run Keyword And Continue On Failure    Wait Until Keyword Succeeds    ${timeout}    5s    Validate Device
@@ -480,6 +480,7 @@
     [Documentation]    Tear down steps for the suite
     Run Keyword If    ${has_dataplane}    Clean Up Linux
     Run Keyword If    ${teardown_device}    Delete All Devices and Verify
+    Close All ONOS SSH Connections
 
 Clear All Devices Then Create New Device
     [Documentation]    Remove any devices from VOLTHA and ONOS & then Create new devices