multicast only received by CoAP server not client

[ToasTer86]

Hey Nordic devzone,

I am tinkering with the following multiprotocol examples: ble_thread_dyn_mtd_coap_cli (client) ble_thread_dyn_template (server)

Currently the client can be controlled using the BSP buttons or a smartphone with the nordic toolbox apps.

When I press a BSP button 2 on the client a multicast message gets send out to the servers to turn on the light. I have altered the ble_thread_dyn_template to setup a connection with a thingy52, on when it does it sends out a multicast message with the thingy52 MAC address and the IPv6 peer address. Only this message is only captured by all the other servers not the client in this case.

I altered the function :

static void thread_coap_init(void)
{
    thread_coap_configuration_t thread_coap_configuration =
    {
        .coap_server_enabled                = true,
        .coap_client_enabled                = false,
        .coap_cloud_enabled                 = false,
        .configurable_led_blinking_enabled  = false,
    };

    thread_coap_utils_init(&thread_coap_configuration);
}

To set the coap_server_enabled to true, where before the coap_client_enabled was set to true. My application still works the same but the ble_thread_dyn_mtd_coap_cli example is still not picking up my multicast messages.

It most likely has to do with the scope in the function : thread_coap_utils_multicast_light_request_send

switch (scope)
{
case THREAD_COAP_UTILS_MULTICAST_LINK_LOCAL:
    p_scope = "FF02::1";
    break;

case THREAD_COAP_UTILS_MULTICAST_REALM_LOCAL:
    p_scope = "FF03::1";
    break;

default:
    ASSERT(false);
}             

If i check the IPv6 thread addressing site I can see the following multi cast adressing 'domains'

ff02::1	Link-Local	All FTDs and MEDs
ff02::2	Link-Local	All FTDs and Border Routers
ff03::1	Mesh-Local	All FTDs and MEDs
ff03::2	Mesh-Local	All FTDs and Border Routers

Would I need to alter the switch to include any of the other multicast scopes?

Thanks in advance for any tips

[ToasTer86]

Hey Hung Bui,

Thanks for your reply, they way I have set it is now :

thread_configuration_t thread_configuration =
{
    .role                  = RX_ON_WHEN_IDLE,
    .autocommissioning     = true,
    .poll_period           = 2500,
    .default_child_timeout = 10,
};

Checking the definition that should be a powered device:

typedef enum
{
    RX_ON_WHEN_IDLE = 0,  /**< Powered device */
    RX_OFF_WHEN_IDLE,     /**< Sleepy End Device */
} thread_role_t;

Can I use multicast messages to reach end devices, or should I use unicast messages for that ?

But it would kind of combat the general idea of a mesh network if I would always need to unicast a message to an end node. So shouldn't it be possible to reach endnode's using a multicast message?

If not, what way could I force the client to not take a end-device role?

Thanks again Hung