> Source: [sk178128](https://support.checkpoint.com/results/sk/sk178128)

# sk178128 - The cell modem in 1500 appliances does not reconnect to the LTE network when the LTE network is disturbed.

| Property | Value |
|----------|-------|
| Solution ID | sk178128 |
| Date Created | 2022-03-01 |
| Last Modified | 2022-07-12 |
| Technical Level | General |
| Products | Spark Firewall (Locally Managed) |
| Versions | R81.10.X |
| Platform | 1570R, 1500 |

## Symptoms

- * The cell modem in 1500 appliances does not reconnect to the LTE network when the LTE network is disturbed.

* Centrally managed appliances revert back to the previous firmware version after reboot when they are upgrading as they cannot connect to the Management Server through LTE.

## Cause

Some LTE devices for the region's modem vendors are not supported in the firmware.

## Solution

1. Apply [R80.20.35 GA](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk174683) firmware which is without modem support.

2. [Contact Check Point Support](https://www.checkpoint.com/support-services/contact-support/) to get a Hotfix for this issue.

A Support Engineer will make sure the Hotfix is compatible with your environment before providing the Hotfix.

For faster resolution and verification please collect [CPinfo](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk92739) files from the Security Management and Security Gateways involved in the case.

**Hotfix installation instructions:**   
Refer to [sk168597 - How to install a Hotfix](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk168597).

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