I diged into this and even git cloned the sources of
the mmsd-tng (the next generation) from
git clone https://gitlab.com/kop316/mmsd.git
My modem says about the IMSI:
AT+CIMI
262075156772756
OK
The config file for the mmsdtg is in ~/.mms/modemmanager/mms but
with broken default values, only the IMSI is the correct one from
my SIM (i.e. from my provider FONIC, an O2 spin off):
cat ~/.mms/modemmanager/mms
[Modem Manager]
CarrierMMSC=http://mms.invalid
MMS_APN=apn.invalid
CarrierMMSProxy=NULL
DefaultModemNumber=NULL
AutoProcessOnConnection=true
AutoProcessSMSWAP=true
IMSI=262075156772756
...
The IMSI is explained here (in German, because the English version
of the page is not very good structured):
IMSI (MCC Mobile Country Code, 3 digits, MNC Mobile Network Code, 2 or 3 disgits)
262 07 is: Telefónica Germany GmbH & Co. oHG
I modified the above file according the settings in
https://www.apnsettings.org/de/fonic-de/
cat ~/.mms/modemmanager/mms
[Modem Manager]
CarrierMMSC=http://10.81.0.7:8002
MMS_APN=pinternet.interkom.de
CarrierMMSProxy=82.113.100.6:8080
DefaultModemNumber=NULL
AutoProcessOnConnection=true
AutoProcessSMSWAP=true
IMSI=262075156772756
and rebooted; now it seems correctly set:
purism@pureos:~$ sudo journalctl -b -0 | grep APN
May 06 09:47:30 pureos mmsdtng[787]: ../plugins/modemmanager.c:set_context() Current Context APN: pinternet.interkom.de, mmsd-tng settings MMS APN: pinternet.interkom.de
May 06 09:47:30 pureos mmsdtng[787]: ../plugins/modemmanager.c:set_context() You are connected to the correct APN! Enabling context...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
May 06 09:47:30 pureos mmsdtng[787]: ../src/service.c:mms_service_set_apn() Service APN Set to pinternet.interkom.de
May 06 09:47:40 pureos mmsdtng[787]: ../plugins/modemmanager.c:set_context() Current Context APN: pinternet.interkom.de, mmsd-tng settings MMS APN: pinternet.interkom.de
May 06 09:47:40 pureos mmsdtng[787]: ../plugins/modemmanager.c:set_context() You are connected to the correct APN! Enabling context...
May 06 09:47:40 pureos mmsdtng[787]: ../src/service.c:mms_service_set_apn() Service APN Set to pinternet.interkom.de
purism@pureos:~$
purism@pureos:~$ sudo journalctl -b -0 | grep 'Operator ID'
(empty)
Update: sending a MMS with a Jpeg file went fine.