Hi,
I use the Q2687 modem, with an AT&T SIM card (with roaming).
The modem was tested in Europe (the Netherlands) and everything worked fine.
Now the modem is in the USA (Cleveland).
And I get a CME Error 812 “Bearer connection failure: GPRS network failure”, with start bearer (AT+WIPBR=4,6,0)
The commands send to modem are:
AT+WOPEN=1
AT+WIPCFG=1
AT+WMBS=4,0
AT+CSQ (untill field is ok)
AT+WIPBR=6,1
AT+WIPBR=2,6,11,“isp.cingular”
AT+WIPBR=2,6,0,""
AT+WIPBR=2,6,1,""
AT+WIPBR=6,6,1
AT+WIPBR=4,6,0
=> ERROR (812 with CME enabled)
Can anybody help me out?
The SIM has GPRS, the GSM band should be fine, the APN should be fine, I’m out of options 
Thanks,
Sander