Re: A general (learning) query

[Dan Williams <dcbw redhat com>]

On Wed, 2012-06-13 at 02:09 +0530, Ajay Garg wrote:
> Bad News.
> 
> 
> ########################################################
> Welcome to minicom 2.5
> 
> OPTIONS: I18n 
> Compiled on Feb 24 2011, 11:25:55.
> Port /dev/ttyUSB0
> 
> Press CTRL-A Z for help on special
> keys                                                          
>                                                                                                  
> AT S7=45 S0=0 L1 V1 X4 &c1 E1
> Q0                                                                 
> OK                                                                                               
> AT
> +CGDCONT=?                                                                                     
> ERROR
> ########################################################

Two things to check:

1) is the SIM correctly inserted?
2) Is this really a GSM/UMTS modem?  What's the brand and model number?

Dan

> 
> Regards,
> Ajay
> 
> On Wed, Jun 13, 2012 at 1:54 AM, Dan Williams <dcbw redhat com> wrote:
>         On Wed, 2012-06-13 at 01:44 +0530, Ajay Garg wrote:
>         > Mauricio,
>         >
>         > Exactly, I guess there must be some algorithm, so as to
>         identify the
>         > init string that the modem likes (brute-force would be like
>         searching
>         > a pearl in the desert).
>         >
>         >
>         > Any how, on some more googling (I am still awaiting a proper
>         > methodology to do this), I tried with the
>         following /etc/wvdial.conf
>         > (I just added the "Init3" line to the self-generated file
>         through
>         > "wvdialconf" command)::
>         >
>         >
>         >
>         ########################################################################################################
>         > [Dialer Defaults]
>         > Init2 = ATQ0 V1 E1 S0=0 &C1 &D2
>         > Init3 = AT+CGDCONT=1,"IP","gprs.ancel"
>         > Modem Type = Analog Modem
>         > Phone = *99#
>         > ISDN = 0
>         > Username = ""
>         > Init1 = ATZ
>         > Password = ""
>         > Modem = /dev/ttyUSB0
>         > Baud = 9600
>         >
>         ########################################################################################################
>         >
>         >
>         >
>         > and here is what I get ::
>         >
>         >
>         ########################################################################################################
>         > -bash-4.1# sudo wvdial
>         > --> WvDial: Internet dialer version 1.61
>         > --> Cannot get information for serial port.
>         > --> Initializing modem.
>         > --> Sending: ATZ
>         > ATZ
>         > OK
>         > --> Sending: ATQ0 V1 E1 S0=0 &C1 &D2
>         > ATQ0 V1 E1 S0=0 &C1 &D2
>         > OK
>         > --> Sending: AT+CGDCONT=1,"IP","gprs.ancel"
>         > AT+CGDCONT=1,"IP","gprs.ancel"
>         
>         
>         This just says the modem doesn't like it when you try to send
>         this APN.
>         What does "AT+CGDCONT=?" say?  That tells you the format the
>         modem
>         expects this command to be sent in.  I don't think this
>         actually has
>         anything to do with init strings, since CGDCONT isn't an init
>         string,
>         it's just that wvdial is very simple and that's the only place
>         you can
>         put it when using wvdial.
>         
>         Dan
>         
>         
>