Why Does Dialup Often Fail on a 3G Cellular Interface?
The possible causes are as follows:
1. The 3G data card cannot be identified on the current network or is not supported on the AR.
2. The 3G data card does not match the current network. For example, authentication or service required on the current network is not enabled on the data card or USIM/SIM card. As a result, authentication or negotiation fails in dialup.
3. The 3G data card is not registered with available networks, due to weak signal strength or other reasons. Run the display cellular command to check information about 3G signals. The Current Service Status field must be displayed as "Service available", and the signal strength must be in the allowed range.
4. An incorrect connection mode is configured on the 3G data card. For example, the 3G data card has a SIM card installed but its connection mode is set to WCDMA-only.
5. The USIM/SIM card is not properly installed.
6. The 2G/3G services are not enabled on the USIM/SIM card.
7. The account balance of the USIM/SIM card is insufficient.
8. The USIM/SIM card works incorrectly. Run the display cellular command to check whether the USIM/SIM card is in correct state. The status of the USIM/SIM card must be Ok not Not insert.
9. Check whether 3G configurations, including the dialer number are correct. Check whether PPP authentication is required when the 3G cellular interface accesses a CDMA2000 network.
10. No profile is configured or a profile is incorrectly configured.
11. The 3G cellular interface is shut down using the shutdown command.