Opengear IM7200-L Quick Start Guide Addendum: Cellular Modem Setup

Introduction

This addendum relates to the IM7200-LR, IM7200-LMA, IM7200-LMV, IM7200-LMCR, IM7200-LMCB, and IM7200-LMCT. It should be read in conjunction with the IM7200 Quick Start Guide (QSG).

The IM7200-LR has an internal 4G modem supporting LTE, HSPA+, EDGE, GPRS, and GSM, compatible with most cellular networks in EMEA, APAC, and ANZ. The IM7200-LMA, IM7200-LMV, IM7200-LMCB, IM7200-LMCR, and IM7200-LMCT feature internal 4G LTE modems supporting LTE, HSPA+, GSM, GPRS, and EDGE. By default, each model is set to work with a specific carrier:

These devices can be reprogrammed to work with other carriers' SIM cards, provided by the carrier and installed in-situ.

01. Before powering on the IM7200-L

The IM7200-L features three SMA antenna connectors (1) for cellular diversity and GPS, and a Mini-SIM card slot (2). The kit includes two cellular antennas with 10-foot coaxial cables and magnetic bases. Higher gain and directional antennas can be used if cellular signal strength is an issue.

Device Front Panel Description: The front panel displays the Opengear logo. On the left is a red section with a power button and status LEDs. To the right is a black section with three SMA antenna connectors labeled '1' and a Mini-SIM card slot labeled '2'.

1. Screw the first cellular antenna (or cable) onto the CELL (MAIN) SMA connector and the diversity antenna onto the CELL (AUX) connector.
2. If a GPS antenna is included, screw it onto the GPS connector.
3. Insert the carrier-provided Mini-SIM card into the SIM CARD slot (2). It will lock into place with a click. Ensure the card is inserted with contacts facing downwards.

02. Connect the cellular modem

Ensure the SIM card has been installed as per section 01.

1. Navigate to System > Dial.
2. Select the Internal Cellular Modem tab.
3. Check the "Allow outgoing modem communication" radio button.
4. Enter your carrier's Access Point Name (APN) in the APN field.
5. If using DNS servers other than your carrier's, check the "Override returned DNS servers" box and enter your DNS server addresses in the respective fields.

6. Note: Carriers may provide additional connection details. Often, only the APN is required, leaving other fields blank. If a PIN code was provided for the SIM card, use it to unlock it.

7. Click "Apply Modem Dial Settings" to establish a data connection with your carrier.

03. Check the cellular modem's connection status

1. Navigate to Status > Statistics.
2. Select the Failover and Out-of-band tab.
3. Verify that the "Always on Out-of-Band – Internal Cellular Modem's Connection Status" is "Connected".
4. Note the modem's allocated IP Address and whether it is a public or private IP address.

04. Check the cellular modem's signal strength (RSSI)

1. Navigate to Status > Statistics.
2. Select the Cellular tab.
3. Note the RSSI (received signal strength indication) coverage value. For advanced detail and logging, examine Status > Syslog.

05. Access the IM7200-L over the cellular link

Once the cellular modem connects to your provider's network, remote access to your IM7200-L may be possible. This requires the IM7200-L to have a Public IP address and the remote access path must not have SSH firewalled.

If you have a static Public IP address with your data plan, your IM7200-L will consistently receive the same IP address upon authentication and Internet access. You can then use this static Public IP address for access. By default, only HTTPS, SSH, and ping access are enabled on the Out-of-Band (OoB) connection.

For dynamic Public IP address plans, a DDNS service must be configured. This allows access using the domain name allocated by the DDNS service. Alternatively, for inbound OoB connections, "Call Home" with a Lighthouse or setting up a VPN connection can be used.

Note on IP Addresses: Some carriers' data plans provide dynamic Private or Shared Address IP assignments. These are not directly visible across the Internet. The Failover & Out-of-Band tab on the Status > Statistics page will display your carrier-allocated Private IP address (e.g., 10.x.x.x, 172.16.x.x, 192.168.x.x ranges) or Shared Address (100.64.0.0/10 range). In such cases, "Call Home" or a VPN is required for access.

06. An alternative mode: cellular router

In the default Out-of-Band access mode, the cellular network connection remains active, awaiting incoming access to the IM7200-L or attached serial consoles. The IM7200-L also supports a cellular router mode (disabled by default), which selectively routes IP traffic between the cellular-connected network and the local Ethernet LAN.

To enable routing:

1. Select System > Firewall > Forwarding & Masquerading.
2. Check the "Dialout/Cellular" checkbox under "Network Interface" to designate it as an "Allowed Destination Network".

Network Forwarding enables devices on the local private LAN to connect through to the public network. This configuration establishes the carrier's cellular network as a Destination Network for the Source Network 'Network Interface'.

To enable IP Masquerading (SNAT) for LAN devices to share a single public IP address via the cellular modem:

1. Check "Enable IP Masquerading (SNAT)" on "Dialout/Cellular".
2. Configure Port Forwarding and set Port Rules to allow external users to selectively initiate connections to the masqueraded devices on the LAN.
3. Set the Service Access rules for routed connections to the IM7200-L itself.
4. Configure the devices on the LAN with new Gateway and DNS settings.

07. Another alternative mode: failover

In both the default Out-of-Band access mode and the cellular router mode, the connection to the carrier network is always active. Failover mode offers an alternative: it keeps the internal cellular connection idle in a low-power state.

In this mode, the IM7200-L periodically pings nominated primary and secondary probe addresses over the main network connection. If ping fails, the IM7200-L initiates a cellular connection to the carrier, transparently switching access to this network. When the main network connection is restored, access switches back. Refer to the Opengear User Manual for detailed setup instructions.

08. Other useful cellular functions

'Keep Alive' Watchdog

The 'Keep Alive' Watchdog can force a clean restart of the cellular modem and its services to mitigate carrier issues, such as preventing disconnection during idle periods. This service periodically pings a nominated IP address. Each ping attempt sends a configurable number of pings; failure occurs if none are successful. By default, keep-alive pings are sent at 30-second intervals, with each attempt sending five 64-byte packets.

Note: Ping replies may incur charges. The default setup generates approximately 50MB of data usage monthly on top of normal usage.

Monitoring cellular data usage

A Cellular Data Usage Alert triggers a notification when traffic levels approach a user-defined limit, such as nearing the data allocation in the carrier's plan.

Alert Configuration Example:

• Alarm Sensor Alert: An alert is triggered when an alarm condition occurs.
• Cellular Data Usage Alert: An alert is triggered when cellular data usage is exceeded.
• Alert Trigger Settings:
  • Data Limit: e.g., 1000 MB
  • Time Window: e.g., 14 Days, 0 Hours, 0 Minutes
• Apply Alert To: Select "Internal Cellular Modem" to apply the alert to the cellular modem(s).

SMS initiated cellular connection

The IM7200-L can accept SMS text messages to trigger the cellular radio signal and connect to the carrier AP. This function utilizes the Auto Response feature and calls a custom script. For details, consult the Opengear Knowledge Base.