+
+### Filtering capabilities
+
+It is possible to limits received event notifications into minimum and maximum boundaries as well as doing frequency thinning. This is possible using the argument filter with one or more of the filters available :
+
+* frequency: specify in Hertz the frequency which will be used to getting notified of new CAN events for the designated signal. If, during the blocked time, further changed CAN messages are received, the last valid one will be transferred after the lockout with a RX_CHANGED.
+* min: Minimum value that the decoded value needs to be above to get pushed to the subscribed client(s).
+* max: Maximum value that the decoded value needs to be below to get pushed to the subscribed client(s)
+
+Order doesn't matter neither the number of filters chosen, you can use one, two or all of them at once.
+
+Usage examples :
+
+```json
+low-can subscribe {"event": "messages.engine.speed", "filter": { "frequency": 3, "min": 1250, "max": 3500}}
+low-can subscribe {"event": "messages.engine.load", "filter": { "min": 30, "max": 100}}
+low-can subscribe {"event": "messages.vehicle.speed", "filter": { "frequency": 2}}
+```
+
+## Using CAN utils to monitor CAN activity
+
+You can watch CAN traffic and send custom CAN messages using can-utils preinstalled on AGL target.
+
+To watch watch going on a CAN bus use:
+
+```bash
+candump can0
+```
+
+Or for an USB CAN adapter connected to porter board:
+
+```bash
+candump can1
+```
+
+Send a custom message:
+
+```bash
+cansend can0 ID#DDDDAAAATTTTAAAA
+```
+
+You can also replay a previously dumped CAN logfiles. These logfiles can be found in _can_samples_ directory under Git repository. Following examples use a real trip from an Auris Toyota car.
+
+Trace has been recorded from a CAN device `can0` so you have to map it to the correct one you use for your tests.
+
+Replay on a virtual CAN device `vcan0`:
+```bash
+canplayer -I trip_test_with_obd2_vehicle_speed_requests vcan0=can0
+```
+
+Replay on a CAN device `can0`:
+```bash
+canplayer -I trip_test_with_obd2_vehicle_speed_requests can0
+```
+
+Replay on a CAN device `can1` (porter by example):
+```bash
+canplayer -I trip_test_with_obd2_vehicle_speed_requests can1=can0
+```