---
title: "Add Mobile Broadband GSM Interface"
slug: "add-mobile-broadband-gsm-interface"
updated: 2026-05-19T11:48:24Z
published: 2026-05-19T11:48:24Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zpesystems.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add Mobile Broadband GSM Interface

Mobile Broadband interfaces can be configured when a mobile broadband modem is available to the device. The Nodegrid SR family (NSR, GSR, BSR, LSR, HSR) support built-in modems available as optional add-ons. For all other units, external modems can be used.

The created interfaces allow the system to establish an Internet connection most used for failover options. Users and remote systems can directly access the device through a mobile connection (if supported by the ISP).

An APN (provided by the carrier) is required for all cellular connections. For more information on APNs, see [https://support.zpesystems.com/portal/kb/articles/what-is-the-apn-for-my-nsr-or-bsr-to-connect-to-4g-lte](https://support.zpesystems.com/portal/kb/articles/what-is-the-apn-for-my-nsr-or-bsr-to-connect-to-4g-lte)

1. Go to the *NETWORK::CONNECTIONS* page
2. Click **Add** (displays dialog)
3. Enter **Name**
4. On Type drop-down, select **Mobile Broadband GSM** (dialog changes)![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678382092050.png)
5. On **Interface drop-down**, select one
6. Enter **Description**
7. If **Connect Automatically** checkbox is selected, connection is automatically established at startup
8. **Set as Primary Connection** checkbox (defines interface as the primary connection. Only one interface can be the primary.)
9. If **Enable LLDP advertising and reception through this connection** checkbox is selected: On **Port ID** drop-down, select one. On **Port Description** drop-down, select one

![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678379685443.png)
10. Select **Block Unsolicited Incoming Packets** checkbox (automatically blocks all inbound connections on the interface)
11. Select the **Enable Connection Health Monitoring** checkbox. When you enable this option:
  1. A modem resets if the IP address is not reachable
  2. A modem power cycles if the reset fails

![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678382444923.png)
    1. Select **Ensure Connection is Up**checkbox
    2. Enter **IP Address**
    3. Enter **Interval (hours)** (default: 24)

> [!NOTE]
> Note:
> 
> The Connection Health Monitoring process works as follows:
> 
> 1. When **Connect Automatically** is enabled (under *Network :: Connections*), the system first checks if the cellular connection is **Up**.
> 2. If the connection is **Up**, it verifies both the IP address and the health monitoring interval.
> 3. If the IP address is unreachable, the interface goes **Down**and comes **Up**again.
> 4. If the modem successfully obtains an IP address, it means that the modem is functional.
> 5. If the modem fails to connect:
>   1. The system attempts to reset the modem.
>   2. If the reset fails, the modem undergoes a power cycle.
12. In *IPv4 Mode*menu, select one:
  - **No IPv4 Address** radio button
  - **DHCP** radio button
  - Enter IPv4 details:
  - 
    - (optional) **IPv4 DNS Server**
    - **IPv4 DNS Search** (defines a domain name for DNS lookups)
    - **IPv4 Default Route Metric**
    - **Ignore the obtained IPv4 Default Gateway** checkbox
    - **Ignore the obtained DNS server** checkbox
13. In *IPv6 Mode*menu, select one:
  - **No IPv6 Address** radio button
  - **Address Auto Configuration** radio button
  - Enter IPv6 details:
  - 
    - (optional) **IPv6 DNS Server**
    - **IPv6 DNS Search** (defines a domain name for DNS lookups)
    - **IPv6 Default Route Metric**
    - **Ignore the obtained IPv6 Default Gateway** checkbox
    - **Ignore the obtained DNS server** checkbox
14. In *Mobile Broadband Connection*menu:
  1. Enter **SIM-1 Phone Number**
  2. On SIM*-1 APN Configuration*menu, select one:
    - **Automatic** radio button
    - If the **Manual** radio button is selected (expands dialog), enter details:
  3. Enter SIM-1 details:
    - **SIM-1 User name** (user name to unlock the SIM)
    - **SIM-1 Password**
    - **SIM-1 Access Point Name (APN)**
    - Enter **SIM-1 Personal Identification Number (PIN)**
    - **SIM-1 MTU (**bytes – can be set to ‘auto’ = 1500 bytes)
    - **Enable the Data Usage Monitoring**checkbox (monitors the data usage and signal strength at regular intervals and provides historical data). If selected (expands dialog):
      - 
        - **SIM-1 Data Limit Value (GB)** (monthly data limit)
        - **SIM-1 Data Warning (%)** (percentage that triggers an event notification when reached)
        - **SIM-1 Renew Day** (day to reset accumulated data)
  4. If **Enable IP Passthrough**checkbox is selected (expands dialog):
    - **Ethernet Connection** drop-down, select one (selection varies depending on the device)
    - **MAC Address** (if blank, the system uses DHCP to get the device)
    - **Port Intercepts** (any ports that should NOT pass through the Nodegrid device)
    - If **Enable Global Positioning System (GPS)** checkbox is selected (expands dialog):

![](https://cdn.document360.io/763c5fb1-b9af-4ccd-9ad6-cf28ae4cd5a3/Images/Documentation/image-1678383664736.png)
      - Enter **Polling Time (min).**
      - On the **GPS Antenna** drop-down, select one (Shared GPS/Rx diversity(aux) antenna, Dedicated Active GPS antenna, Dedicated Passive GPS antenna)
15. (if available) Select the **Enable Second SIM card** checkbox. Repeat entries for SIM-2 settings. There is a setting **Active SIM card** that can designate SIM-2 as the primary SIM card
16. Click **Save**