How to Troubleshoot Robustel Gateway（RobustOS System） Unable to Obtain IP Address After Inserting SIM Card
Overview
A normal SIM card's internet access primarily involves two steps: registration and dial-up. Many users find that after inserting a SIM card into a Robustel gateway, the SIM card can register with the operator but cannot obtain an IP address through dial-up. This document is compiled based on past experience in troubleshooting such issues, aiming to assist with problem resolution.
Prerequisites
- 1 x Activated SIM card, correctly inserted into the gateway's WWAN1 slot
- A computer capable of accessing the gateway's web management interface
- Administrator account (e.g., admin) privileges
- 1 x Robustel gateway
Step-by-Step Troubleshooting Guide
Step 1: Check APN Configuration
Configure APN (Access Point Name): This is the most common cause of failure to obtain an IP address. If the APN settings are incorrect, the gateway cannot access the operator's mobile data network. Log in to the gateway management interface, navigate to 【Interface】 -> 【Link Manager】, and manually check whether the APN information provided by the operator has been added for the corresponding slot link (e.g., WWAN1). Be sure to confirm the APN details with the operator or distributor
Step 2: Check Primary Link Configuration
Set WWAN1 as the Primary Link: Incorrect network link configuration is another common issue that may prevent the SIM card's IP address from being displayed. This often occurs when the WAN or WLAN link was used during testing but was not switched back in the actual application scenario. Further confirmation can be made in 【Interface】 -> 【Link Manager】.
The following shows an incorrect configuration, where the WLAN link is set as the primary link and the backup link is set to "None." This will prevent the SIM card network from being used and hide the obtained IP address:
The following shows a correct configuration, where the WWAN1 slot (with the SIM card inserted) is set as the primary link. This enables the use of the SIM card network and displays the obtained IP address:
Step 3: Check On-Site Signal Issues
Check Signal Strength: For 4G/5G networks, the Reference Signal Received Power (RSRP) is a critical indicator. If the RSRP value is consistently below -100 dBm, it indicates a weak signal. In such cases, adjusting the gateway's location or antenna setup may be necessary:
Revision History
Version | Date | Author | Description of Changes |
1.0 | 2025-10-29 | Tony Li | Initial document creation |
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