Hello, I made some progress debugging the issue. It is an issue with my Google Pixel 9 and how it interacts with a sysmocom SIM card and MCC/MNC 999/70.
I have deactivated 5G and IMS using the scripts provided with pysim. Even with 5G and IMS deactivated and 2G activated as the only technology for this SIM card (using *#*#INFO#*#*), the phone tries to access Volte and/or Voice over Wi-Fi. In the *#*#INFO#*#* menu, I see a switch from 2G to LTE for a split second. With MCC/MNC 999/70 on the SIM Card does not give me any option concerning Volte or Voice over Wi-Fi. When I switch the MNC/MNC on the SIM card to 001/01, I see an option on the phone to disable Volte and Voice over Wi-Fi. When I do disable Volte and Voice over Wi-Fi, the 2G disassociation issue goes away. When I switch to another MCC/MNC such as 310/014, I do not have access to the Volte and Voice over Wi-Fi option and the issue persists. I can stay on 001/01 for the time being to work around the issue. If out of curiosity, you want me to continue to do some debugging, I can continue to do some experiments. Thank you all for your help! Christoph Am 27. August 2025 07:42:09 UTC schrieb "Tomcsanyi, Domonkos" <d...@tomcsanyi.net>: >Also try using the tool called scat or similar tools to get a pcap of the >signaling between your phone and the network, it will be immensely helpful not >only now but later on as well. >It would immediately tell you if this theory is valid or not, because you’d >see in the pcap the reject coming from the network. > >Cheers, >Domi > >> >> 26.08.2025 dátummal, 19:57 időpontban Keith <ke...@rhizomatica.org> írta: >> >> >>> On 26/08/2025 11:50, Christoph Quirin Lauter wrote: >>> Hello Keith, >>> >>> that sounds exactly like what I am observing. >>> >>> I will have to buy a USB SIM reader and understand how pysim works. >> >> Before you do that, check that you do not have a SIM reader around >> someplace, for example, my DELL Latitude 5590 has one built right in, >> although it is a full (credit card sized) slot and I am a little reluctant >> to put in cards with the SIM reinserted into a spacer and card, in case it >> slips and gets stuck inside, requiring dissasembly to get it out. >> >>
