diff --git a/common/core.h b/common/core.h
index 78cbb0f..812a9b5 100644
--- a/common/core.h
+++ b/common/core.h
@@ -41,8 +41,12 @@
 Status DisablePonIf_(uint32_t intf_id);
 Status EnableUplinkIf_(uint32_t intf_id);
 Status DisableUplinkIf_(uint32_t intf_id);
+unsigned NumNniIf_();
+unsigned NumPonIf_();
 Status OmciMsgOut_(uint32_t intf_id, uint32_t onu_id, const std::string pkt);
 Status OnuPacketOut_(uint32_t intf_id, uint32_t onu_id, const std::string pkt);
+Status ProbeDeviceCapabilities_();
+Status ProbePonIfTechnology_();
 Status UplinkPacketOut_(uint32_t intf_id, const std::string pkt);
 Status FlowAdd_(int32_t onu_id,
                 uint32_t flow_id, const std::string flow_type,
diff --git a/common/main.cc b/common/main.cc
index 2898219..b211cfb 100644
--- a/common/main.cc
+++ b/common/main.cc
@@ -15,6 +15,7 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 #include <iostream>
+#include <unistd.h>
 
 #include "server.h"
 #include "core.h"
@@ -29,6 +30,18 @@
         return 1;
     }
 
+    // Wait for successful activation before allowing VOLTHA to connect. 
+    // This is necessary to allow the device topology to be dynamically
+    // queried from driver after initialization and activation is complete.
+    int maxTrials = 300;
+    while (!state.is_activated()) {
+        sleep(1);
+        if (--maxTrials == 0) {
+            std::cout << "ERROR: OLT/PON Activation failed" << std::endl;
+            return 1;
+        }
+    }
+
     RunServer();
 
     return 0;