Posts made by Kolja Vornholt

I can confirm the issue. I can reproduce it. The problem occurs not due to LTE-M but due to this specific APN (m2m.public.nl). @Uta will take care of this

I will look into that. In the meantime:
Have you already tested IPv4 ?

@aliza-izaton As mentioned earlier, I strongly recommend using a python-based solution.

@rxtx Perfect!

@rxtx

AT+COPS=1,2,"20416"
2022-02-17T10:57:35.077Z DEBUG modem << OK
2022-02-17T10:57:38.329Z DEBUG modem >> AT+CFUN=1
2022-02-17T10:57:38.378Z DEBUG modem << OK

You turn on the radio after you perform the manual attach. This looks strange for me. Not sure whether the manual attach works in this case. Please turn on the radio (at+cfun=1) before you perform the manual attach. usually you can can choose the RAT type while doing the manual attach. That would be:

AT+COPS=1,2,"20416",7

7 for LTE-M on your module. Try this pls. not sure whether that works on your module.

BR,
Kolja

@Adriaan Can you share the pcap file with us?

You think that he button does not close the TCP socket correctly (meaning without sending FIN)?

@magnatron would be great of you could share your experience/problem/solution with us.

@magnatron Have you done a network search already?

@Adriaan Could you share a screenshot of your Wireshark Log with us?

@magnatron couple of minutes
You could also do a network search (at+cops=?) to check whether you see Vodafone’s network.

@Adriaan I would recommend to do a tcpdump (but limit to the port you are using) and save it fo a file (-w option). then analyze this dump with Wireshark.

@magnatron
Automatic Attach can take a lot of time. How long have you waited?

@magnatron
Let me pls summarize your issue in my words to check I understood your problem correctly.

• You’ve set your modem to band 20-only.
• You want to use auto-attach (at+cops=0) but it does not find a network
• However, manual attach (with selecting Vodafone’s network) does work

Is that right?

BR,
Kolja

Hi Adriaan,

Yes, thats true. I also made the same observations. For such “advanced” testing purposes, I strongly recommend to use python using the socket library. The easiest way would be to start a new thread for each incoming device and a more advanced setup would be with one thread for incoming traffic and one thread for outgoing traffic using asyncio.

BR,
Kolja

As roaming is more or less transparent for the device as well as backend-end server, this recommendation formulated here https://forum.iotcreators.com/topic/594/data-packet-size still applies.

Have you tried to ping the destination? Pls try with both URL and IP. Which tariff plan do you have?