AT+CGDCONT? in u-blox TOBY-L2

[Aleksander Morgado]

Hey,

When listing PDP contexts on the u-blox Toby L2 module, I see that the
actual APN string is suffixed with an extra string specifying MCCMNC
of the network.

When first registered in the LTE network, the PDP context 4 gets
activated (default EPS bearer) and shows up as follows:

debug_log(): (ttyACM2): --> 'AT+CGDCONT?<CR>'
debug_log(): (ttyACM2): <-- '<CR><LF>+CGDCONT:
4,"IP","airtelwap.es.MNC001.MCC214.GPRS","10.1.115.80",0,0,0,0,0,0<CR><LF>'

When I then request a new connection to the "ac.vodafone.es" APN,
ModemManager creates a new PDP context as follows:

debug_log(): (ttyACM2): --> 'AT+CGDCONT=5,"IP","ac.vodafone.es"<CR>'
debug_log(): (ttyACM2): <-- '<CR><LF>OK<CR><LF>'

The issue is that when I disconnect and reconnect using the same APN,
the new list of existing APNs shows the following:

debug_log(): (ttyACM2): --> 'AT+CGDCONT?<CR>'
debug_log(): (ttyACM2): <-- '<CR><LF>+CGDCONT:
4,"IP","airtelwap.es.MNC001.MCC214.GPRS","10.1.115.80",0,0,0,0,0,0<CR><LF>'
debug_log(): (ttyACM2): <-- '+CGDCONT:
5,"IP","ac.vodafone.es.MNC001.MCC214.GPRS","",0,0,0,0,0,0<CR><LF>'
debug_log(): (ttyACM2): <-- '<CR><LF>OK<CR><LF>'

This is, the APN in the PDP context that I created now has the
"MNC001.MCC214.GPRS" suffix, and the logic looking for the PDP context
fails to find the same one, so a new one is created.... and at the end
we get a new one for each connection attempt.

Interestingly, if the module is power cycled, the new CGDCONT? list
does show the original APN name.

This is the first time I've seen it, so I wonder if I should just
change the logic looking for a matching APN in the PDP context to
match per prefix instead of per full string. E.g. Looking for
"ac.vodafone.es" would match if "ac.vodafone.es.MNC001.MCC214.GPRS" is
found.

Or, should I instead do this some u-blox specific change?

What do you guys think?

-- 
Aleksander
https://aleksander.es