UDP - Mancata ricezione pacchetti in NBIOT mode

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

Øyvind — Mon, 18 May 2026 07:53:57 GMT

Hello again Maurizio, apologies for the late reply.

Our team have looked into this, testing with 1nce and Hologram SIM and UDP data reception. This seem to be working with NB-IoT on Finnish network provider, they were able to receive UDP data in Finland just fine while attached to NB-IoT using your modified UDP sample. Note that this is not using VPN functionality. All in all, this could indicate an issue on the network side where data packets are possibly not properly cached in NB-IoT.

[quote user="maupicco"]1NCE has now collected the information and forwarded it to the roaming partner (Vodafone) for their analysis.[/quote]

Have 1NCE received any further feedback fra Vodafone? Have you been able to test with native Vodafone SIM?

Kind regards,
Øyvind

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

Øyvind — Wed, 13 May 2026 11:35:27 GMT

Thank you! This is much appreciated!

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

maupicco — Wed, 13 May 2026 11:00:49 GMT

I ran a new trace a few minutes ago. I'm attaching the trace file.

devzone.nordicsemi.com/.../trace_2D00_2026_2D00_05_2D00_13T10_2D00_55_2D00_54.473Z.mtrace

Kind regards,

Maurizio

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

Øyvind — Wed, 13 May 2026 09:55:47 GMT

Thanks for clarifying. I have forwarded to our network experts. Do you happen to have the .mtrace file from Cellular Monitor as well? This will provide more details. The initial comment from our team is that in Cellular-Monitor-NBIOT-device.pcapng log, the UE receives paging from the network, but network does not deliver UDP payload and just releases RRC connection.

Kind regards,
Øyvind

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

maupicco — Wed, 13 May 2026 07:47:43 GMT

Hi Øyvind,

I'll try to clarify how the 1NCE VPN works. When you purchase a 1NCE SIM card, you get the option to connect the server to a network using a VPN that can directly reach devices with fixed addresses for each SIM card. This way, packets to and from the server use the VPN to communicate with the devices. For the UDP reception issue I reported, I also contacted 1NCE, which monitored the UDP traffic and verified that outgoing messages from my server are correctly arriving on their network and are correctly routed to the IP address of the device being tested.

I'm attaching the log file I received from 1NCE.

devzone.nordicsemi.com/.../2026_2D00_05_2D00_06_5F00_nbiot_5F00_dl_5F00_traffic_5F00_udp.pcapng

The device notices the packet that has been sent to it because, systematically, after a few seconds (usually 1 to 10 seconds), it switches from the RCC Idle state to the RCC Connect state, but immediately afterwards it returns to the RCC Idle state without the socket receiving any data.

1NCE has now collected the information and forwarded it to the roaming partner (Vodafone) for their analysis.

Kind regards

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

Øyvind — Wed, 13 May 2026 07:26:25 GMT

Hello maupicco , apologies for the late reply. I will have a look at the wireshark traces that you have provided.

[quote user=""]VPN between my UDP service and the 1nce network (to eliminate NAT issues)[/quote]

Could you please elaborate more on what this means? Are you able to also provide the raw modem traces from Cellular Monitor?

Thanks.

Kind regards,
Øyvind

RE: UDP - Mancata ricezione pacchetti in NBIOT mode

Achim Kraus — Sun, 03 May 2026 08:10:13 GMT

In my experience, receiving just +CSCON=1 but no data, happens in some networks, while in others you may receive the data. In my case it ends up in only sending a "wake up" signal, and then poll the application data on wake-up from the device.