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Cisco Meraki Documentation

MG21 Troubleshooting Guide

Resolving common MG issues

Common Connection States

Below are the possible Connection States reported on the Local Status Page:

Connection State Status
Initializing Cellular gateway is doing initial checks and validating the status of the modem and SIM.
Locked If a PIN is detected and requires configuration, the cellular gateway will stop here until resolved.
Enabled The cellular gateway will begin preparing the internal modem for connection.
Registered The modem is registered to a cellular network. When stuck here, it could mean additional configuration is required such as Authentication or APN.
Connected Bearer configurations have been set (automatically or manually configured). The cellular gateway should be in working order.
Disconnected New overrides will disconnect the modem for a short period before resuming initialization with the updated configuration.
Disabled Cellular gateway software has shutdown the modem. The device should automatically recover from this state shortly.

No Lights When the Cellular Gateway Is Powered On 

  • Try connecting the cellular gateway to a different power source

  • Try using a different Ethernet cable if using a PoE injector

  • Try another AC adapter, if using one

No Link Lights When Connecting a Device 

  • Check that the RJ45 head is not loose or damaged

  • Make sure the connected device is on and working

    • Try connecting the device to another port on the same gateway

    • Try connecting the device to a switch or some other network cellular gateway

  • Swap the Ethernet cable with a known working cable

  • Perform a factory reset on the device

Sporadic Connectivity or Solid Amber Power LED

If experiencing unstable cellular connectivity and/or a solid amber power LED, indicating the gateway is unable to reach the Meraki dashboard, please attempt the following steps to help diagnose and isolate the issue:

  • With the cellular gateway turned off, check the SIM card tray and validate the SIM card is properly seated

    • Check for any damage to the SIM tray cage

    • Check SIM card alignment if card is not properly set

  • On external antenna models, start with an inspection for any physical damage on the antennas and loose or missing antennas

    • Improper seating of antennas could affect signal quality and prevent a stable cellular connection from being formed between the cellular gateway and tower

  • Determine if the MG is in an optimal environment and direction

    • Check that the direction of the cellular gateway is optimally facing the desired cellular tower

    • The MG21 has a slight bias gain depending on the direction of the face. The MG21E dipole antennas are designed for omnidirectional gain

    • Ensure no physical obstructions are causing lower signal quality. Fresnel zones effect cellular as well because it is also a wireless technology like WiFi

    • The cellular gateway, while designed with an IP67 rating, still operates within certain physical limits. Evaluate placement of the MG and the variables in the environment

  • Check cellular gateway's Local Status Page and understand the reported telemetry to ensure a quality connection

    • Make sure the signal strength and quality is sufficient. If the modem connection type is on 4G/LTE, the RSRP and RSRQ ideally would be high

    • Check that the band and carrier are appropriate. Roaming on carrier networks and incorrect bands could affect connectivity

Cloud Connectivity Prerequisites

Below are some prerequisite checks to evaluate to determine if the cellular gateway can communicate with the dashboard or provide a data connection.

  • Determine if the connectivity issue possibly due to misconfiguration of the cellular modem in regards to the data plan

    • Check if there is a PIN set on the SIM card and if it is locked out. If a SIM card PIN has too many failed attempts it will require a PUK code to unlock

    • Check that the proper bearer configurations are set. Override APN, PIN, username and password, and authentication if required by the carrier

  • Validate with the carrier that the data plan is valid with an active subscription

    • Check data usage and restrictions on the SIM

    • Check that the data plan allows the cellular gateway to use it. Certain carriers restrict data plans by IMEI

    • Check if the SIM card is paired specifically with the IMEI of another device

    • Occasionally, moving SIM cards between a previously working device and the cellular gateway without checking with the carrier first could lead to troubleshooting the wrong issue

    • Data plans can be negotiated with the carriers. The data plans provide the quantum of data for uploading/downloading over the network. Post expiry of the data plan, the MG21 cannot communicate to dashboard or provide an active data connection

  • Check the cellular uplink IP, connection to internet, and then connection to the cloud

    • Sometimes SIMs will assign an IP but prevent data from passing, preventing internet access

  • Leverage an existing network to allow the cellular gateway to check in with Safe Mode

    • Make sure there are no upstream firewalls that could be blocking the cellular gateway's management traffic.

    • Allow the cellular gateway to check in and update to the latest firmware with Safe Mode

    • If the MG is in Safe Mode and checking into Dashboard, Support will be able to run diagnostics remotely to further assist with troubleshooting

    • If all else fails, try performing a factory reset on the device. See the MG21 installation guide for steps on performing a factory reset.

The MG41 cellular gateway uses 6 to 8 megabytes a day of data for telemetry on dashboard and connection monitoring when the unit is idle. Any additional Cisco Meraki devices that are added to the MG41 may increase data usage further. Cisco Meraki products are cloud connected devices that report telemetry into Dashboard for network monitoring purposes. The usage will be reduced in future firmware updates.

Signal Values Tables

It is recommended to not rely solely on signal bars when troubleshooting. Always check the proper signal values to get more accurate readings. For transparency, the following values are how the MG cellular gateway calculates signal bars. Between different vendors the signal bars could mean different things, meaning the same signal bar value could equate to substantially different RSRP and RSRQ values. When deploying the MG cellular gateway, it is important to take into account the values below for a signal type to find optimal signal quality. The RSRP and RSRQ values are relevant when the modem type is in 4G/LTE. When the modem type is in 3G the RSCP and Ec/No is used. In both types, the lower of the two values will be translated into the universal signal bars equivalent.

Signal Bar


4G Type 3G Type
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

 A simple rule of thumb when it comes to these values is the closer it is to 0, the stronger the signal.