Distance for the Node to connect to the gateway MQTT-SN ?

RE: Distance for the Node to connect to the gateway MQTT-SN ?

Deri — Thu, 18 Mar 2021 16:06:31 GMT

$sudo nano /etc/paho-mqtt-sn-gateway.conf
..
..
# UDP6
GatewayUDP6Port=47193
GatewayUDP6Broadcast=ff33:40:fdde:ad00:beef:0:0:1
GatewayUDP6If=wpan0
GatewayUDP6Hops=5
..
..

RE: Distance for the Node to connect to the gateway MQTT-SN ?

jebentancour — Mon, 30 Mar 2020 18:13:32 GMT

Can you show me where did you set it?

RE: Distance for the Node to connect to the gateway MQTT-SN ?

LucD — Tue, 14 Jan 2020 06:09:55 GMT

Adding some lines the paho MQTT-SN gateway code to set the multicast hop (in my case I picked 5) fixed the issue, as the default value is 1 if you do not set this option and thus the GWINFO message doesn't get broadcasted past the initial hop.

RE: Distance for the Node to connect to the gateway MQTT-SN ?

LucD — Tue, 14 Jan 2020 02:52:27 GMT

I've just setup a network sniffer and the GWINFO msg is broadcasted with hoplimit = 1, I assume this will prevent if from reaching any nodes down the network tree. How can this setting be changed? I don't know if this is hardcoded in the ncp firmware, set from the OpenThread Border Router software or something in the paho MQTT-SN gateway config.

RE: Distance for the Node to connect to the gateway MQTT-SN ?

LucD — Tue, 14 Jan 2020 02:37:38 GMT

I've been working on the Thread and MQTT-SN in combination with the nRF52840 for a while now and started out from the SED examples provided, I'm using the paho gateway and everything works fine when SED nodes are directly connected to the border router for gateway discovery. Now I'm running into similar issues that nodes cannot discover the gateway if they connect via another router node(so there is one hop in between the node that wants to join and the gateway). The SEARCHGW message is send successfully and gateway replies with a GWINFO broadcast, but the node trying to connect never seems to get this broadcast message and give a gateway search timeout response.

This severely limits the use of Thread, as only direct links to the gateway are currently possible. Even with radio RX on when idle the node doesn't seem to receive the broadcast message send to ff03::1, what could be causing this?

RE: Distance for the Node to connect to the gateway MQTT-SN ?

AndreasF — Tue, 20 Aug 2019 13:11:27 GMT

Hi.

How do you verify the Thread topology?

Can you please use the Thread topology monitor and post a screenshot of the topology?

And also provide me with some radio traffic dump using the nRF Sniffer?

Thanks.

Best regards,

Andreas

RE: Distance for the Node to connect to the gateway MQTT-SN ?

Giang — Mon, 19 Aug 2019 13:39:45 GMT

Hi I checked and this is result.

If I put NCP -> Node 1 -> Node 2 -> Node 3 -> Node 4.

And I send discovery gateway from Node 4 . The message go to NCP, and NCP return a INFOGATEWAY. But this message go to Node 1 -> Node 2 -> Node 3. But Node 4 can't receiver. Although I have put Node 4 pole near Node 3. But Node 4 still can't receiver message.

RE: Distance for the Node to connect to the gateway MQTT-SN ?

Giang — Mon, 19 Aug 2019 07:14:56 GMT

Hi AndreasF,

Sorry because slow reply. I very busy.

When I put NCP -> Node 1 -> Node 2 in a straight line. Next, I send discovery message from Node 2 to NCP. The purpose is to Node 2 can connect to MQTTSN-GATEWAY via Node 1, If I turn off Node 1, Node 2 can't send any message. So when I send discovery connect from Node 2. I see in Raspi, It can receiver this message. But in Node 2 I see it run event MQTTSN_SEARCH_GATEWAY_NO_GATEWAY_FOUND.

Below is log in Node 2 and raspi :

Thank you !!

RE: Distance for the Node to connect to the gateway MQTT-SN ?

AndreasF — Wed, 14 Aug 2019 12:45:59 GMT

Hi.

Do you have any chance to provide me with some logs?

Best regards,

Andreas

RE: Distance for the Node to connect to the gateway MQTT-SN ?

Giang — Wed, 14 Aug 2019 12:13:18 GMT

Thank for reply,

1. Yep, When I put NCP - Node1 - Node2 in a straight line. Node 1 can connect to MQTT Gateway but Node 2 can't. It mean Node 2 can't send discovery and connect message to NCP.

2. If I put Node 1 near NCP and connect Node 1 to MQTT Gateway. Then I put Node 2 near NCP and connect Node 2 to MQTT Gateway. Then I put NCP - Node1 - Node2 in a straight line. Node 2 can send data to MQTT Gateway and control Node 1 as pub-sub Node.

So I don't understand why Node 2 can send discovery and connect message to NCP.

It all used otUdpSend function

RE: Distance for the Node to connect to the gateway MQTT-SN ?

AndreasF — Wed, 14 Aug 2019 11:58:40 GMT

Hi.

[quote user=""]But when I send search gateway msg, connect msg from publish (subscribe) Node to NCP. Seem it can't send as mesh network. I have to put Node in the coverage area of NCP then it can discovery and connect to Gateway. If I put NCP --> Node 1 --> Node 2 in a straight line. Node 1 can connect to mqtt gateway, but node 2 can't . But I can ping from Node 2 to Node 1 and NCP. [/quote]

Do you mean that if you create this network:

NCP - Node1 - Node2

Then:

Node 1 can connect to the MQTT-SN Gateway
Node 2 cannot connect to the MQTT-SN Gateway

Please clarify this.

[quote user=""]If I connect Node1 and Node 2 to MQTT gateway and put NCP --> Node 1 --> Node 2 in a straight line. I can send data from Node 1 and Node 2 to NCP as mesh network. [/quote]

I don't really understand this, can you please try to explain some more?

It would be really helpful if you can provide traffic data using the nRF Sniffer for both situations. See here how to use it.

Best regards,

Andreas