# Problem to send downlink via MQTT clients

**URL:** <https://www.thethingsnetwork.org/forum/t/problem-to-send-downlink-via-mqtt-clients/69128>\
**Category:** Uncategorized\
**Created:** [September 6, 2024, 8:11am UTC](https://www.thethingsnetwork.org/forum/t/problem-to-send-downlink-via-mqtt-clients/69128 "2024-09-06T08:11:25Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![maulazz](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/m/7ea924/32.png) [@maulazz](https://www.thethingsnetwork.org/forum/u/maulazz)\
**Post date:** [September 6, 2024, 8:11am UTC](https://www.thethingsnetwork.org/forum/t/problem-to-send-downlink-via-mqtt-clients/69128/1 "2024-09-06T08:11:25Z")

</div>

In the past I had no problem to send downlink messages via MQTT client. Yesterday, after many months, I tryed the same procedure but no downlink message was inserted in the downlink queue.  
I am using MQTT BOX as client and I had no problem to connect and to receive messages from the subscribed topic.

The topic to publish is: v3/nps0000000000000001@ttn/devices/eui-/down/push where is the DEVEUI of the device that I would like to configure.

The Payload Type is: Strings / JSON / XML / Characters

The payload is:  
{  
“downlinks”: [{  
“f\_port”: 1,  
“frm\_payload”: “AAG7AASjCwEDrNg=” ,  
“priority”: “NORMAL”  
}]  
}

after presing the PUBLISH button I obtain the following result:  
Topic to publish  
v3/nps0000000000000001@ttn/devices/eui-0004A30B0103ACD8/down/push  
QoS  
Retain  
Payload Type  
e.g: {‘hello’:‘world’}  
Payload  
{  
“downlinks”: [{  
“f\_port”: 1,  
“frm\_payload”: “AAG7AASjCwEDrNg=” ,  
“priority”: “NORMAL”  
}]  
}  
Publish  
{ “downlinks”: [{ “f\_port”: 1, “frm\_payload”: “AAG7AASjCwEDrNg=” , “priority”: “NORMAL” }] }  
topic:v3/nps0000000000000001@ttn/devices/eui-0004A30B0103ACD8/down/push, qos:0, retain:false

but no downlink message is displayed in the Live Data section for the selected end device.

The downlink transmission is correctly working from the Messaging section.