diff --git a/tracetools_analysis/analysis/callback_duration.ipynb b/tracetools_analysis/analysis/callback_duration.ipynb
index 432f5c4..3e6f044 100644
--- a/tracetools_analysis/analysis/callback_duration.ipynb
+++ b/tracetools_analysis/analysis/callback_duration.ipynb
@@ -100,6 +100,10 @@
     "    if owner_info is None:\n",
     "        owner_info = '[unknown]'\n",
     "\n",
+    "    # Filter out internal subscriptions\n",
+    "    if '/parameter_events' in owner_info:\n",
+    "        continue\n",
+    "\n",
     "    # Duration\n",
     "    duration_df = data_util.get_callback_durations(obj)\n",
     "    starttime = duration_df.loc[:, 'timestamp'].iloc[0].strftime('%Y-%m-%d %H:%M')\n",
@@ -173,6 +177,11 @@
     "\n",
     "colour_i = 0\n",
     "for obj, symbol in callback_symbols.items():\n",
+    "    # Filter out internal subscriptions\n",
+    "    owner_info = data_util.get_callback_owner_info(obj)\n",
+    "    if not owner_info or '/parameter_events' in owner_info:\n",
+    "        continue\n",
+    "\n",
     "    duration_df = data_util.get_callback_durations(obj)\n",
     "    source = ColumnDataSource(duration_df)\n",
     "    duration.title.align = 'center'\n",
@@ -215,7 +224,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.6.9"
+   "version": "3.8.5"
   }
  },
  "nbformat": 4,
diff --git a/tracetools_analysis/analysis/sample_data/converted_pingpong b/tracetools_analysis/analysis/sample_data/converted_pingpong
index ab8f88c..2dabe6e 100644
Binary files a/tracetools_analysis/analysis/sample_data/converted_pingpong and b/tracetools_analysis/analysis/sample_data/converted_pingpong differ
diff --git a/tracetools_analysis/tracetools_analysis/data_model/ros2.py b/tracetools_analysis/tracetools_analysis/data_model/ros2.py
index 75f4c6f..28ebb22 100644
--- a/tracetools_analysis/tracetools_analysis/data_model/ros2.py
+++ b/tracetools_analysis/tracetools_analysis/data_model/ros2.py
@@ -78,6 +78,10 @@ class Ros2DataModel(DataModel):
                                             'period',
                                             'tid'])
         self.timers.set_index(['timer_handle'], inplace=True, drop=True)
+        self.timer_node_links = pd.DataFrame(columns=['timer_handle',
+                                                      'timestamp',
+                                                      'node_handle'])
+        self.timer_node_links.set_index(['timer_handle'], inplace=True, drop=True)
 
         self.callback_objects = pd.DataFrame(columns=['reference',
                                                       'timestamp',
@@ -142,6 +146,11 @@ class Ros2DataModel(DataModel):
     ) -> None:
         self.timers.loc[handle] = [timestamp, period, tid]
 
+    def add_timer_node_link(
+        self, handle, timestamp, node_handle
+    ) -> None:
+        self.timer_node_links.loc[handle] = [timestamp, node_handle]
+
     def add_callback_object(
         self, reference, timestamp, callback_object
     ) -> None:
@@ -205,6 +214,9 @@ class Ros2DataModel(DataModel):
         print('Timers:')
         print(self.timers.to_string())
         print()
+        print('Timer-node links:')
+        print(self.timer_node_links.to_string())
+        print()
         print('Callback objects:')
         print(self.callback_objects.to_string())
         print()
@@ -215,7 +227,6 @@ class Ros2DataModel(DataModel):
         print(self.callback_instances.to_string())
         print()
         print('Lifecycle state machines:')
-        print()
         print(self.lifecycle_state_machines.to_string())
         print()
         print('Lifecycle transitions:')
diff --git a/tracetools_analysis/tracetools_analysis/processor/ros2.py b/tracetools_analysis/tracetools_analysis/processor/ros2.py
index d340e05..a37731c 100644
--- a/tracetools_analysis/tracetools_analysis/processor/ros2.py
+++ b/tracetools_analysis/tracetools_analysis/processor/ros2.py
@@ -63,6 +63,8 @@ class Ros2Handler(EventHandler):
                 self._handle_rcl_timer_init,
             'ros2:rclcpp_timer_callback_added':
                 self._handle_rclcpp_timer_callback_added,
+            'ros2:rclcpp_timer_link_node':
+                self._handle_rclcpp_timer_link_node,
             'ros2:rclcpp_callback_register':
                 self._handle_rclcpp_callback_register,
             'ros2:callback_start':
@@ -198,6 +200,14 @@ class Ros2Handler(EventHandler):
         callback_object = get_field(event, 'callback')
         self.data.add_callback_object(handle, timestamp, callback_object)
 
+    def _handle_rclcpp_timer_link_node(
+        self, event: Dict, metadata: EventMetadata,
+    ) -> None:
+        handle = get_field(event, 'timer_handle')
+        timestamp = metadata.timestamp
+        node_handle = get_field(event, 'node_handle')
+        self.data.add_timer_node_link(handle, timestamp, node_handle)
+
     def _handle_rclcpp_callback_register(
         self, event: Dict, metadata: EventMetadata,
     ) -> None:
diff --git a/tracetools_analysis/tracetools_analysis/utils/ros2.py b/tracetools_analysis/tracetools_analysis/utils/ros2.py
index 761b3e5..1b2a902 100644
--- a/tracetools_analysis/tracetools_analysis/utils/ros2.py
+++ b/tracetools_analysis/tracetools_analysis/utils/ros2.py
@@ -228,14 +228,18 @@ class Ros2DataModelUtil(DataModelUtil):
         :param timer_handle: the timer handle value
         :return: a dictionary with name:value info, or `None` if it fails
         """
-        # TODO find a way to link a timer to a specific node
         if timer_handle not in self.data.timers.index:
             return None
 
+        node_handle = self.data.timer_node_links.loc[timer_handle, 'node_handle']
+        node_handle_info = self.get_node_handle_info(node_handle)
+        if node_handle_info is None:
+            return None
+
         tid = self.data.timers.loc[timer_handle, 'tid']
         period_ns = self.data.timers.loc[timer_handle, 'period']
         period_ms = period_ns / 1000000.0
-        return {'tid': tid, 'period': f'{period_ms:.0f} ms'}
+        return {**node_handle_info, 'tid': tid, 'period': f'{period_ms:.0f} ms'}
 
     def get_publisher_handle_info(
         self,