Using Dial-up Networking to Make a GPRS Connection

Using Dial-up Networking to Make a GPRS Connection


With most GSM/GPRS modems (except for some PC card modems that allow GPRS access through a network connection without using dial-up networking), you will need to define a dial-up networking connection in Windows that tells the gateway how to use the modem to make a GPRS connection.


A beta version of NowSMS is available that supports the ability to use Android phones as GSM modem devices for both sending and receiving SMS and MMS messages. This beta release is also available for download via the download links.

Supporting Android phones as modems is significant for several reasons:

  • LTE Support – LTE based Android devices can provide higher speed support for MMS sending and receiving.
  • Network Compatibility – Some mobile operators (and modem device manufacturers) assume that modems are used for internet access only and disable SMS and/or MMS support for modems. This is not an issue for Android phones.
  • CDMA Support – For years, US based customers have asked us about modems that can support Verizon and Sprint. Android phone support allows us to support those network operators using both CDMA and high speed LTE.
  • Broad Device Availability – For customers interested in trying NowSMS, it is far easier to locate or acquire an Android device than a conventional modem.
  • MMS Performance – With conventional GSM modems, MMS performance is limited by the mode switching required to switch between data and SMS channels. There are no mode switching delays mixing SMS and MMS traffic on Android devices.
  • Reliability – USB connectivity (and driver quality or lack thereof) is a major limitation for systems with multiple conventional GSM modems. For Android phones, the NowSMS server connects to the Android phones over WiFi. Modems can even be located in different physical locations to maximize signal strength. (The NowSMS server communicates over WiFi to a new app running on the Android phone.)


Before continuing, you will need to determine the GPRS APN (Access Point Name), the IP address of the WAP gateway, and the MMSC Message Server URL that are used for sending/receiving MMS via your operator network. These settings are operator dependent, and it may be advisable to check the MMS configuration settings on a working mobile phone to determine the correct settings. Note that your mobile operator possibly has multiple GPRS APNs and multiple WAP gateways, and you need the settings that are appropriate for MMS, not for WAP browsing or general internet connectivity.


To define a dial-up networking connection, you will first need to ensure that a modem driver has been configured for your modem in Windows (this is done in the Windows Control Panel under Phone and Modem Options). If you do not have a modem driver for your modem, it is possible to use any of the "Standard" or "Generic" modem drivers that can be manually installed in the Control Panel.


Dial-up Networking connections are then defined under "Network and Dial-up Connections" dialog in the Windows Control Panel. Note that if you are using multiple GSM/GPRS modems, you can define multiple Dial-up networking profiles.


The process will vary slightly between different versions of Windows. The following steps describe the process under Windows 2000:


Select "Make New Connection".


The "Network Connection Wizard" is displayed. Select "Next".



The "Network Connection Type" dialog will be displayed. Select "Dial-up to private network", and select "Next".




On the "Select a Device" dialog, select the GSM/GPRS modem that you will be using for this GPRS connection, and select "Next".



Enter "*99#" as the phone number to dial, and do not use Windows dialing rules.



The system might prompt you whether to create this connection for all users, or only for the current user. Select "All Users".


The final step of the wizard is to assign a name for the Dial-up networking connection. You will need to configure the Now SMS/MMS Gateway to use this named connection, so assign a name that is easy to remember.



Usually after the "Network Connection Wizard" is complete, Windows will automatically display a "Connect" dialog for the connection that was just created. If you do not see this dialog, return to the Windows Control Panel, Select "Network and Dial-up Connections", and select your connection. The "Connect" dialog should then be displayed:



Before testing the configuration, we need to define some additional properties for the GPRS connection, so select the "Properties" button.


The "Properties" dialog, should display a screen similar to the following:



Go to the "Networking" tab. In the "Components checked are used by this connection" list, ensure that only the "Internet Protocol (TCP/IP)" component is selected. Then highlight that component, and select "Properties".



The "Properties" dialog should have an "Advanced" button. Select the "Advanced" button.




Under the "Advanced" settings, a checkbox should appear for "Use default gateway on remote network". Under most configurations, this box should NOT be checked.



When "Use default gateway on remote network" is checked, this means that whenever this connection is active, all internet connectivity will be routed through this connection by default. If you are using a laptop to connect to the internet via GPRS, that may be desirable. However, for a typical configuration of the Now SMS/MMS Gateway, that is not desirable, therefore this setting should not be enabled.


Select "OK" several times to save your changes before returning to the "Connect" dialog.


There is one more configuration setting that must be applied, so select "Cancel" to exit the "Connect" dialog.


Return to the Windows Control Panel, and select "Phone and Modem Options". Select the "Modems" page. Highlight the modem that you will be using, and select "Properties".




Select the "Advanced" page of the properties dialog.



In the "Extra Initialization commands" field, you need to define the name of the GPRS APN that is used for sending/receiving MMS messages. This command takes the format: AT+CGDCONT=1,"IP","GPRS.APN". This will initialize the modem to connect to the proper GPRS APN. Select "OK" to save this setting.


Note that if you are using a phone as a modem, instead of a dedicated modem, perhaps only to send MMS messages, the above setting could confuse existing settings on your phone. This settings command assigns a GPRS CID (connection id) of "1" to the defined GPRS APN. Your phone will already have connection ids defined for existing profile settings on your phone. In this case, you may want to consult the documentation for you phone to determine how to read existing CID values from profile settings on your phone. Rather than defining this "extra initialization command", you can leave this blank, and instead configure the appropriate CID # in the Dial-up Networking Connection instead.


Return to the Windows Control Panel, select "Network and Dial-up Connections", and select the dial-up networking connection that was defined earlier.



If your mobile operator requires a username and password for GPRS connections, then supply those parameters here. Even if your mobile operator does not require a username or password, be sure to check the "Save password" box, so that Windows will remember these settings.


If you are using a GPRS connection id (CID) other than "1", change the "Dial" phone number from "*99#" to "*99***x#", where "x" is the appropriate CID number.


Now select "Dial" to verify that your Dial-up Networking profile is able to connect without errors. Disconnect the connection after verifying that it can connect without errors.