How Do I Locate the Cause for a 3G Dial-up Access Failure?

Run the display cellular interface-number network command to check the Current Service Status field.

If the Current Service Status field displays Service Available, the 3G service is available. Perform the following operations to further check the router configuration:

1. Check whether the dialer number is configured correctly.
2. If the 3G interface is connected to the WCDMA network or a network that is compatible with the WCDMA network, check whether the APN is configured correctly
3. Check whether the authentication mode, user name, and password are consistent with those provided by the carrier.
4. Check whether the dialer ACL is configured correctly.

If the Current Service Status field displays No Service or Emergency, the 3G service is unavailable. If the 3G service is unavailable, perform the following operations:

1. If the 3G interface is connected to the WCDMA network or a network that is compatible with the WCDMA network, run the display cellular interface-number network command to check the Mobile Country Code (MCC), Mobile Network Code (MNC), and Mobile Operator Information fields and check whether the PLMN selected by the 3G modem is consistent with that of the carrier.

   If the 3G interface is connected to the CDMA2000 network or a network that is compatible with the CDMA2000 network, you can skip this step.

2. Run the display cellular interface-number network command to check the Current Network Connection field and check whether the type of the network connected to the 3G modem is correct.
3. Run the display cellular interface-number radio command to check the Current RSSI field and received signal strength. If the RSSI is larger than or equal to -85 dBm, signals are stable and reliable.

   • If the Current RSSI field displays a value smaller than -85 dBm, perform the following operations:

     1. Check whether the angle of the antennas is proper. The angle of antennas affects signal receiving and sending.
     2. Check whether the 3G/2G signal in the area is strong.

   • If the Current RSSI field displays Unknown, perform the following operations:

     1. Check whether the 3G data card is supported by the device.
     2. Check whether the 3G hardware or 3G antenna is damaged, not properly installed, or not fastened.
     3. Check whether the area is covered with 3G/2G signals.
4. Check the SIM, USIM, or UIM card.
   1. Contact the carrier to confirm whether 3G/2G services are enabled on the SIM, USIM, or UIM card and whether the users owe fees.

   2. Run the display cellular interface-number security command to check the SIM Status field and check whether the SIM, USIM, or UIM card status is normal.

      If the SIM Status field displays Not insert, the SIM, USIM, or UIM card is not installed properly.

5. Run the display cellular interface-number security command to check PIN Status and check whether the PIN status is normal.