diff --git a/src/forecaster/service/TODO.txt b/src/forecaster/service/TODO.txt
index 95d3fba03084bd1104d49abafc8eb426af5d8c35..e1c8532026f8e35ccbbe307000e380b22b9d103e 100644
--- a/src/forecaster/service/TODO.txt
+++ b/src/forecaster/service/TODO.txt
@@ -1,3 +1,20 @@
+
+Use a smaller network:
+INFO     forecaster.tests.Tools:Tools.py:75 Discovering Devices and Links...
+INFO     forecaster.tests.Tools:Tools.py:104   Found 22 devices and 462 links...
+
+ERROR    forecaster.service.ForecasterServiceServicerImpl:Decorator.py:233 ForecastTopologyCapacity exception
+Traceback (most recent call last):
+  File "/home/tfs/tfs-ctrl/src/common/method_wrappers/Decorator.py", line 220, in inner_wrapper
+    reply = func(self, request, grpc_context)
+  File "/home/tfs/tfs-ctrl/src/forecaster/service/ForecasterServiceServicerImpl.py", line 94, in ForecastTopologyCapacity
+    link_capacities[link.link_id] = link.attributes
+TypeError: unhashable type: 'LinkId'
+
+
+
+
+
 test case:
 - instantiate Context and Monitoring
 - populate topology
diff --git a/src/forecaster/tests/test_unitary.py b/src/forecaster/tests/test_unitary.py
index 8e2c8821a2f4df25492ca750f9bfdb5f2128c2fd..0be9e5f06dc224667c5f4764ab47e0964d39f41f 100644
--- a/src/forecaster/tests/test_unitary.py
+++ b/src/forecaster/tests/test_unitary.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import logging, pandas, pytest
+import json, logging, pandas, pytest
 from typing import Dict, Tuple
 from common.Constants import DEFAULT_CONTEXT_NAME, DEFAULT_TOPOLOGY_NAME
 from common.proto.context_pb2 import ContextId, TopologyId
@@ -37,11 +37,14 @@ ADMIN_TOPOLOGY_ID = TopologyId(**json_topology_id(DEFAULT_TOPOLOGY_NAME, context
 
 CSV_DATA_FILE = 'forecaster/tests/data/dataset.csv'
 #CSV_DATA_FILE = 'forecaster/tests/data/dataset2.csv'
+DESC_DATS_FILE = 'forecaster/tests/data/descriptor.json'
 
 @pytest.fixture(scope='session')
 def scenario() -> Tuple[pandas.DataFrame, Dict]:
     df = read_csv(CSV_DATA_FILE)
     descriptors = compose_descriptors(df)
+    with open(DESC_DATS_FILE, 'w', encoding='UTF-8') as f:
+        f.write(json.dumps(descriptors))
     yield df, descriptors
 
 def test_prepare_environment(