Troubleshooting MG41 and MG51 Cellular Gateways
Troubleshooting cloud connectivity issues
Use the following prerequisite checks to evaluate whether the cellular gateway can communicate with the dashboard or provide a data connection.
Troubleshooting steps
- Determine if the connectivity issue is possibly due to a misconfiguration of the cellular modem in regard to the data plan.
- Check whether the SIM card has a Personal Identification Number (PIN) set and whether the PIN is locked. If the SIM card PIN has too many failed attempts, the SIM card requires a PIN Unlock Key (PUK) code to unlock.
- Check that the gateway has the proper bearer configurations set. Override the "SIM x data session setting" if the carrier requires it.
- Validate with the carrier that the data plan is active and has a valid subscription.
- If a user reports that the SIM card is activated but the MG41 or MG51 is offline, use DM logging to capture the logs and check for the carrier's "Attach reject" Non-Access Stratum (NAS) message.
- Check data usage and restrictions on the SIM.
- Confirm the data plan supports the cellular gateway. Certain carriers restrict data plans by International Mobile Equipment Identity (IMEI).
- Check whether the SIM card pairs specifically with the IMEI of another device. Moving SIM cards between a previously working device and the cellular gateway without checking with the carrier first can lead to troubleshooting the wrong issue.
- Check the cellular uplink IP address, the connection to the internet, and then the connection to the cloud.
- Sometimes SIMs will assign an IP address but prevent data from passing, which can prevent internet access.
- Use an existing network to allow the cellular gateway to check in with Safe Mode/Wired WAN Mode.
- Confirm that no upstream firewalls blocking the cellular gateway's management traffic.
- Use Safe Mode to allow the cellular gateway to check in and update to the latest firmware.
- If the MG is in Safe Mode and checking into the dashboard, Meraki Support will be able to run diagnostics remotely to further assist with troubleshooting.
- As a final step, perform a factory reset on the device. See the MG41/51 installation guide for factory reset steps.
Note: Refer to AT command Reference docs for more information. The Access Point Name (APN) can change between connection generations.
DM logging on the local status page
Integrated Diagnostic Monitor (DM) logging debugs cellular WAN interface issues on the MG41 and MG51. The DM logs contain northbound Long Term Evolution (LTE) and Universal Mobile Telecommunications System (UMTS) messages exchanged between the modem and the service provider's cellular network. DM logs help determine whether a problem originates on the MG41 or MG51 or within the service provider network.
Launch the DM logging tool from the Configure tab on the local status page.
If there are persistent issues with the cellular WAN, engage Meraki Support for further troubleshooting assistance.
Resolving common MG Issues
Refer to DM Logs Review and Licensing Restrictions for more information.
Common connection states
The local status page reports the following connection states:
| Connection State | Status |
| Connected | APN configurations have been set (automatically or manually configured). The cellular gateway should be in working order. |
| Not Connected | New overrides will disconnect the modem for a short period before resuming initialization with the updated configuration. |
For passthrough troubleshooting, refer the documentation on MG IP Passthrough.
The MG51/E does not support 3G/UMTS.
Troubleshooting hardware issues: no power lights
Troubleshooting steps
- Connect the cellular gateway to a different power source.
- Use a different Ethernet cable if using a PoE injector.
- Try another AC adapter, if using one.
Troubleshooting connectivity issues: no link lights
Troubleshooting steps
- Check that the RJ45 head is not loose or damaged.
- Confirm the connected device is on and working.
- Connect the device to another port on the same gateway.
- Connect the device to a switch or another cellular gateway on the network.
- Swap the Ethernet cable with a known working cable.
- Perform a factory reset on the device.
Troubleshooting performance degradation: amber LED
If the cellular gateway has unstable cellular connectivity or shows a solid amber power LED, the gateway cannot reach the dashboard. Use the following steps to diagnose and isolate the issue.
Troubleshooting steps
- Check the SIM card. With the gateway turned off, confirm the SIM card is inserted correctly and properly aligned in the slot.
- Verify the SIM slot status. Check the local status page to confirm the SIM slot displays as active.
- Inspect the antennas (external antenna models). Look for physical damage, and confirm the antennas are not loose or missing.
- Evaluate the gateway's environment and direction. Confirm the cellular gateway faces the desired cellular tower. The MG41 and MG51 have a slight bias gain depending on the direction the unit faces, while the MG41E and MG51E dipole antennas provide omnidirectional gain.
- Check for physical obstructions. Fresnel zone effects can reduce cellular signal quality, similar to Wi-Fi.
- Evaluate the placement of the gateway. The cellular gateway has an IP67 rating but still operates within certain physical limits.
- Check the location for RF interference. Keep the gateway a few feet away from high-power lines or cables, since proximity to these can cause RF interference and affect MG41 or MG51 performance.
- Review signal telemetry on the local status page. Confirm the signal strength and quality are sufficient. For a 4G/LTE connection, the Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ) values should ideally be high, as shown in the following table.
| 4G/5G Type | 4G/5G Type | 3G Type | 3G Type | |
|---|---|---|---|---|
| Signal Bar | RSRP Range (dBm) | RSRQ Range (dB) | RSCP | Ec/No |
| 5 | RSRP >= -83 | RSRQ >= -7 | RSCP >= -80 | EC/NO >= -9 |
| 4 | -83 > RSRP >= -92 | -7 > RSRQ >= -10 | -80 > RSCP >= -90 | -9 > EC/NO >= -11 |
| 3 | -92 > RSRP >= -102 | -10 > RSRQ >= -13 | -90 > RSCP >= -100 | -11 > EC/NO >= -13 |
| 2 | -102 > RSRP >= -111 | -13 > RSRQ >= -16 | -100 > RSCP >= -106 | -13 > EC/NO >= -15 |
| 1 | -111 > RSRP >= -140 | -16 > RSRQ >= -20 | -106 > RSCP >= -125 | -15 > EC/NO >= -19 |
- Check the band and carrier. Roaming on carrier networks can affect connectivity.
Note: If the MG51 or MG51E cannot connect to the internet after multiple reboots or with a provisioned SIM card, low signal conditions could be the cause. The local status page displays detailed signal information, as shown below.
The signal could be as bad as shown below:
After you move the device to a location with better signal conditions, the device automatically reconnects.
Understanding MG51 5G connectivity (5G NSA vs. SA)
5G NSA and 5G SA overview
The MG51 uses a 5G technology called 5G Non-Standalone (NSA). The alternative technology is 5G Standalone (SA). The core difference between 5G NSA and 5G SA is the control signaling of the Radio Access Network (RAN). 5G NSA anchors control signaling to the 4G LTE network and requires an established 4G LTE connection before establishing 5G service. A 5G NSA connection builds on top of an existing 4G LTE connection.
5G SA handles control signaling directly on the 5G network, which allows a 5G SA connection to be established purely over 5G without a 4G LTE connection. 5G NSA technology serves as a stepping stone that allows providers to integrate 5G connectivity into existing networks more quickly and ease the transition from 4G LTE to full 5G SA networks.
Viewing radio status on the dashboard
View radio status in the Uplink tab of the MG status page on the dashboard. For the MG51, the radio status section displays both current 4G and 5G radio status, including current bands and signal strength.
When the MG establishes a 5G connection, the radio status displays both the 4G LTE and 5G NSA radio status.
