AWS IoT Core - mqtt_helper connection was unexpectedly closed - Telstra/Simbase

RE: AWS IoT Core - mqtt_helper connection was unexpectedly closed - Telstra/Simbase

Øyvind — Tue, 27 Aug 2024 08:38:38 GMT

Hi Craig, thanks for your patience with this case. I've had our modem trace experts have a look at this and it seems it seems that Telstra does not have PSM support for Simbase subscription and all connections are closed when device goes to PSM. I would suggest reaching out to Telstra and ask them.

In the other two logs with different SIMs the data connections are restored when device wakes up from PSM.

Kind regards,
Øyvind

RE: AWS IoT Core - mqtt_helper connection was unexpectedly closed - Telstra/Simbase

Craig12 — Tue, 20 Aug 2024 05:01:19 GMT

Øyvind,

Thanks for you input. I have attached traces for a successful Hologram session, and also a successful Simbase session. With Simbase we generally get a couple of sessions that terminate prematurely with no data flow, and then it comes good.

I've had a look over the wireshark traces myself, and it appears after a reconnection, there is no dataflow from Simbase. I can see the device send a TCP packet to AWS, but there is nothing in return. It retries four times before giving up.

On successful sessions, there are normally four packets back and forths - with two replies back from AWS (via the Simbase network.)

I don't know if that is a unstream issue between the Telstra RAN and Simbase, or something I'm doing wrong.

Regards,

Craig

devzone.nordicsemi.com/.../Hologram-Success.zip devzone.nordicsemi.com/.../Simbase-Success.zip

RE: AWS IoT Core - mqtt_helper connection was unexpectedly closed - Telstra/Simbase

Øyvind — Fri, 16 Aug 2024 12:58:27 GMT

Hello,

From the initial look at the modem trace it appears that the device is disconnected i.e. connection reset, afterwards the device will timout.

Are there any special Packet Data Networks (PDN) settings that are needed to connect to the network?

[quote user=""]I note another ticket on DevZone with something similar. When looking at the AT commands, they just happen to be using Simbase on the Telstra Network (50501)[/quote]

It does look similar but I'm not able to tell from my initial look. The DevZone case you referred to does receive ESM 50 -

Cause #50 – PDN type IPv4 only allowed This ESM cause is used by the network to indicate that only PDN type IPv4 is allowed for the requested PDN connectivity.

There could be an issue with IPv6 vs IPv4. Could you please try setting the following settings in your prj.conf

CONFIG_NET_IPV4=y

CONFIG_NET_IPV6=n

Also, could you please collect a modem trace from the Hologram SIM and/or Telstra home SiM?

Thanks!

Kind regards,
Øyvind