(LTE-M) IP connectivity available only 3 seconds every 11 seconds

[Jesper Tiberg]

Hi,

Problem description

I wrote a program that initializes the modem (LTE-M) and goes on to send one UDP packet every second (is just the counter).

The server receives the first 2 or 3 packages, but then the next 10 or 11 are lost. This cycle repeats indefinately.

Does anyone know what's going on here?

PSM and eDRX is disabled (would this matter for outgoing data traffic?)

Cellular network is Telia @ Sweden.

SIM-card: iBasis or Telia LTE-M - same result

For a TCP connection (MQTT for example), this problem is slightly masked since (I guess) the lost packages during the 11 second downtime are resent during the 3 second uptime period - so looking at message logs it seems pretty fine unless you look at the time of arrival.

[Jesper Tiberg]

Status update

TL;DR: Problem resolved by Telia as of today!

Telia updated their network configuration and asked me to check back on the issue. I was not able to replicate the problem anymore. No packets are dropped as far as I can see (I verified using my test app linked earlier in this thread).

The resolution came after a couple of days down time on their LTE-M network (while NB-IoT still worked), in case you've noticed.

Does anyone with the same problem still have the issue, then please report back here.