LTE error codes / call rejections

[Peter Naulls]

I'm looking at these two errors:

wwan (31502): error: couldn't connect the modem: 
'GDBus.Error:org.freedesktop.ModemManager1.Error.MobileEquipment.Unknown: Call 
failed: cm error: lrrc-connection-establishment-failure-not-camped

Tue Feb  8 15:16:38 2022 daemon.notice netifd: wwan (6885): error: couldn't 
connect the modem: 
'GDBus.Error:org.freedesktop.ModemManager1.Error.MobileEquipment.Unknown: Call 
failed: cm error: lrrc-connection-establishment-failure-rejected

I don't know the exact meaning of "camped" here, but I understand it's part
of the cell establishment.  In any case, according to:

http://howltestuffworks.blogspot.com/2011/10/rrc-connection-reestablishment-request.html

(Which is a slightly different error), there may be additional information
in the error - in this case, there's a back off time which is supposed to
be noticed. Certainly both errors seem to happen when the call is made
again "too soon".  The are also accompanied by a user UserAuthenticationFailed
which I imagine is just the fall out error case.

I see enumerations of these errors here:

https://forums.quectel.com/uploads/short-url/yWs5zzBa4x2LyGytODTAUu7WvIf.pdf

But I'm not sure MM handles these enumerations (in particular on page 17) which
might at least be a start to handling this.

Any comments?