During a test with a unit travelling through Europe, we came across an odd issue.
Unit had GPRS and TCP connection to a server through Sweden, Germany and Belgium, but when it reached France, the connection disappeared.
Checking with the unit, it had CGREG indicating roaming, but AT+CGACT=1 returned an ERROR (in this case +CME ERROR: 134)
While in France it had +COPS: 0,2,20801
Unit had GPRS and TCP connection to a server through Sweden and through half of Germany when it lost connection.
Checking with the unit, it had CGREG indicating roaming, but AT+CGACT=1 returned +CME ERROR: 3
Unknown what operator the unit had while it was connected and after it lost connection.
We checked with the operator (Telia) and they are supposed to work with GPRS in either of the cases.
Unit was equipped with a Q2687RD with R7.44 firmware.