diff --git a/agent/test/src/test_enable_olt.cc b/agent/test/src/test_enable_olt.cc
new file mode 100644
index 0000000..0cdb965
--- /dev/null
+++ b/agent/test/src/test_enable_olt.cc
@@ -0,0 +1,162 @@
+/*
+    Copyright (C) 2018 Open Networking Foundation
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "gtest/gtest.h"
+#include "bal_mocker.h"
+#include "core.h"
+
+class TestOltEnable : public ::testing::Test {
+ protected:
+  virtual void SetUp() {
+  }
+
+  virtual void TearDown() {
+    // Code here will be called immediately after each test
+    // (right before the destructor).
+  }
+};
+
+
+// Test Fixture for OltEnable
+
+// Test 1: OltEnableSuccess case
+TEST_F(TestOltEnable, OltEnableSuccess){
+    // NiceMock is used to suppress 'WillByDefault' return errors on using 'NiceMock'.
+    // This is described in https://github.com/arangodb-helper/gtest/blob/master/googlemock/docs/CookBook.md
+    ::testing::NiceMock<BalMocker> balMock;
+    bcmos_errno host_init_res = BCM_ERR_OK;
+    bcmos_errno bal_cfg_get_res = BCM_ERR_NOT_CONNECTED;
+    bcmos_errno olt_oper_res = BCM_ERR_OK;
+
+    Status olt_enable_res;
+
+    // The 'EXPECT_CALL' will do strict validation of input parameters. This may not be relevant for
+    // the current test case. Use 'ON_CALL' instead.
+    // The ON_CALL results in WARNINGs when running tests. Use NickMock instead of directly using BalMocker.
+    // https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#the-nice-the-strict-and-the-naggy-nicestrictnaggy
+    // In below tests '::testing::_' does no validation on argument.
+    ON_CALL(balMock, bcmolt_host_init(::testing::_)).WillByDefault(::testing::Return(host_init_res));
+    ON_CALL(balMock, bcmolt_cfg_get(::testing::_,::testing::_)).WillByDefault(::testing::Return(bal_cfg_get_res));
+    ON_CALL(balMock, bcmolt_oper_submit(::testing::_, ::testing::_)).WillByDefault(::testing::Return(olt_oper_res));
+
+    olt_enable_res = Enable_(1, NULL);
+    ASSERT_TRUE( olt_enable_res.error_message() == Status::OK.error_message() );
+}
+
+// Test 2: OltEnableFail_host_init_fail
+TEST_F(TestOltEnable, OltEnableFail_host_init_fail) {
+    // NiceMock is used to suppress 'WillByDefault' return errors on using 'NiceMock'.
+    // This is described in https://github.com/arangodb-helper/gtest/blob/master/googlemock/docs/CookBook.md
+    ::testing::NiceMock<BalMocker> balMock;
+    bcmos_errno host_init_res = BCM_ERR_INTERNAL;
+    bcmos_errno bal_cfg_get_res = BCM_ERR_NOT_CONNECTED;
+    bcmos_errno olt_oper_res = BCM_ERR_OK;
+
+    Status olt_enable_res;
+
+    // The 'EXPECT_CALL' will do strict validation of input parameters. This may not be relevant for
+    // the current test case. Use 'ON_CALL' instead.
+    // The ON_CALL results in WARNINGs when running tests. Use NickMock instead of directly using BalMocker.
+    // https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#the-nice-the-strict-and-the-naggy-nicestrictnaggy
+    // In below tests '::testing::_' does no validation on argument.
+    ON_CALL(balMock, bcmolt_host_init(::testing::_)).WillByDefault(::testing::Return(host_init_res));
+    ON_CALL(balMock, bcmolt_cfg_get(::testing::_,::testing::_)).WillByDefault(::testing::Return(bal_cfg_get_res));
+    ON_CALL(balMock, bcmolt_oper_submit(::testing::_, ::testing::_)).WillByDefault(::testing::Return(olt_oper_res));
+
+    olt_enable_res = Enable_(1, NULL);
+    ASSERT_TRUE( olt_enable_res.error_message() != Status::OK.error_message() );
+}
+
+// Test 3: OltEnableSuccess_PON_Device_Connected
+TEST_F(TestOltEnable, OltEnableSuccess_PON_Device_Connected) {
+    // NiceMock is used to suppress 'WillByDefault' return errors on using 'NiceMock'.
+    // This is described in https://github.com/arangodb-helper/gtest/blob/master/googlemock/docs/CookBook.md
+    ::testing::NiceMock<BalMocker> balMock;
+    bcmos_errno host_init_res = BCM_ERR_OK;
+    bcmos_errno bal_cfg_get_res = BCM_ERR_OK;
+
+    Status olt_enable_res;
+
+    // The 'EXPECT_CALL' will do strict validation of input parameters. This may not be relevant for
+    // the current test case. Use 'ON_CALL' instead.
+    // The ON_CALL results in WARNINGs when running tests. Use NickMock instead of directly using BalMocker.
+    // https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#the-nice-the-strict-and-the-naggy-nicestrictnaggy
+    // In below tests '::testing::_' does no validation on argument.
+    ON_CALL(balMock, bcmolt_host_init(::testing::_)).WillByDefault(::testing::Return(host_init_res));
+    ON_CALL(balMock, bcmolt_cfg_get(::testing::_,::testing::_)).WillByDefault(::testing::Return(bal_cfg_get_res));
+
+    olt_enable_res = Enable_(1, NULL);
+    ASSERT_TRUE( olt_enable_res.error_message() == Status::OK.error_message() );
+}
+
+// Test 4: OltEnableFail_All_PON_Enable_Fail
+TEST_F(TestOltEnable, OltEnableFail_All_PON_Enable_Fail) {
+    // NiceMock is used to suppress 'WillByDefault' return errors on using 'NiceMock'.
+    // This is described in https://github.com/arangodb-helper/gtest/blob/master/googlemock/docs/CookBook.md
+    ::testing::NiceMock<BalMocker> balMock;
+    bcmos_errno host_init_res = BCM_ERR_OK;
+    bcmos_errno bal_cfg_get_res = BCM_ERR_NOT_CONNECTED;
+    bcmos_errno olt_oper_res = BCM_ERR_INTERNAL;
+
+    Status olt_enable_res;
+
+    // Ensure that the state of the OLT is in deactivated to start with..
+    state.deactivate();
+
+    // The 'EXPECT_CALL' will do strict validation of input parameters. This may not be relevant for
+    // the current test case. Use 'ON_CALL' instead.
+    // The ON_CALL results in WARNINGs when running tests. Use NickMock instead of directly using BalMocker.
+    // https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#the-nice-the-strict-and-the-naggy-nicestrictnaggy
+    // In below tests '::testing::_' does no validation on argument.
+    ON_CALL(balMock, bcmolt_host_init(::testing::_)).WillByDefault(::testing::Return(host_init_res));
+    ON_CALL(balMock, bcmolt_cfg_get(::testing::_,::testing::_)).WillByDefault(::testing::Return(bal_cfg_get_res));
+    ON_CALL(balMock, bcmolt_oper_submit(::testing::_, ::testing::_)).WillByDefault(::testing::Return(olt_oper_res));
+
+    olt_enable_res = Enable_(1, NULL);
+    ASSERT_TRUE( olt_enable_res.error_message() != Status::OK.error_message() );
+}
+
+// Test 5 OltEnableSuccess_One_PON_Enable_Fail : One PON device enable fails, but all others succeed.
+TEST_F(TestOltEnable, OltEnableSuccess_One_PON_Enable_Fail) {
+    // NiceMock is used to suppress 'WillByDefault' return errors on using 'NiceMock'.
+    // This is described in https://github.com/arangodb-helper/gtest/blob/master/googlemock/docs/CookBook.md
+    ::testing::NiceMock<BalMocker> balMock;
+    bcmos_errno host_init_res = BCM_ERR_OK;
+    bcmos_errno bal_cfg_get_res = BCM_ERR_NOT_CONNECTED;
+    bcmos_errno olt_oper_res_fail = BCM_ERR_INTERNAL;
+    bcmos_errno olt_oper_res_success = BCM_ERR_OK;
+
+    Status olt_enable_res;
+
+    // Ensure that the state of the OLT is in deactivated to start with..
+    state.deactivate();
+
+    // The 'EXPECT_CALL' will do strict validation of input parameters. This may not be relevant for
+    // the current test case. Use 'ON_CALL' instead.
+    // The ON_CALL results in WARNINGs when running tests. Use NickMock instead of directly using BalMocker.
+    // https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#the-nice-the-strict-and-the-naggy-nicestrictnaggy
+    // In below tests '::testing::_' does no validation on argument.
+    ON_CALL(balMock, bcmolt_host_init(::testing::_)).WillByDefault(::testing::Return(host_init_res));
+    ON_CALL(balMock, bcmolt_cfg_get(::testing::_,::testing::_)).WillByDefault(::testing::Return(bal_cfg_get_res));
+    // For the the first PON mac device, the activation result will fail, and will succeed for all other PON mac devices.
+    EXPECT_CALL(balMock, bcmolt_oper_submit(::testing::_, ::testing::_))
+                         .WillOnce(::testing::Return(olt_oper_res_fail))
+                         .WillRepeatedly(::testing::Return(olt_oper_res_success));
+
+    olt_enable_res = Enable_(1, NULL);
+    // The OLT activation should succeed if at least one PON mac device activation succeeds.
+    ASSERT_TRUE( olt_enable_res.error_message() == Status::OK.error_message() );
+}