diff --git a/LegacyPlugin_WiFiManagerAPIs.cpp b/LegacyPlugin_WiFiManagerAPIs.cpp
index 5dada6b2..79a19541 100644
--- a/LegacyPlugin_WiFiManagerAPIs.cpp
+++ b/LegacyPlugin_WiFiManagerAPIs.cpp
@@ -250,14 +250,32 @@ namespace WPEFramework
         {
             LOG_INPARAM();
             uint32_t rc = Core::ERROR_GENERAL;
-            string ssid{};
 
-            ssid = parameters["ssid"].String();
             auto _nwmgr = m_service->QueryInterfaceByCallsign<Exchange::INetworkManager>(NETWORK_MANAGER_CALLSIGN);
-            if (_nwmgr)
+            if(_nwmgr)
             {
-               rc = _nwmgr->RemoveKnownSSID(ssid);
-               _nwmgr->Release();
+                std::string ssid = {};
+                if (parameters.HasLabel("ssid"))
+                {
+                    ssid = parameters["ssid"].String();
+                    rc = _nwmgr->RemoveKnownSSID(ssid);
+                }
+                else
+                {
+                    ::WPEFramework::RPC::IIteratorType<string, RPC::ID_STRINGITERATOR>* _ssids{};
+                    rc = _nwmgr->GetKnownSSIDs(_ssids);
+                    if (Core::ERROR_NONE == rc && _ssids != nullptr)
+                    {
+                        string _resultItem_{};
+                        while (_ssids->Next(_resultItem_) == true) {
+                            /* remove all the ssid */
+                            rc = _nwmgr->RemoveKnownSSID(_resultItem_);
+                        }
+                        _ssids->Release();
+                    }
+                }
+
+                _nwmgr->Release();
             }
             else
                 rc = Core::ERROR_UNAVAILABLE;