> For the complete documentation index, see [llms.txt](https://ezr23t.router.works/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ezr23t.router.works/hardware-overview/physical-interfaces.md).

# Physical Interfaces

## Sockets & Interfaces

The 4G Router features multiple SMA-female antenna ports to connect the included 4G paddle and Wi-Fi whip antennas. The antenna sockets are SMA-female connectors. 4G antenna sockets are marked "Mobile. Wi-Fi sockets are marked "Wi-Fi".

<figure><img src="/files/RVgUeUTxhMGcXfJwPxU7" alt=""><figcaption><p>Indoor 4G Router - Physical Interfaces &#x26; Antenna Ports</p></figcaption></figure>

## Indicators

There are four indicators on the router. From top to bottom, the left side is System & Wi-Fi, and the right is SIM1 & SIM2. Below are the indicator descriptions.

<table><thead><tr><th width="125.33333333333331">Indicator</th><th width="93">Status</th><th>Description</th></tr></thead><tbody><tr><td><strong>System</strong></td><td>Green</td><td>This light indicates that the router is receiving power. If it's lit solid green, then the router has booted successfully.</td></tr><tr><td></td><td>Flash</td><td>The router system is booting up. The system indicator flashes while resetting or flashing the firmware.</td></tr><tr><td></td><td>Off</td><td>No light at all indicates that the router is not receiving power. Check the PoE socket connected to the motherboard and check the PoE adapter. You might need to test an alternate power socket if the router doesn't power on.</td></tr><tr><td><strong>Wi-Fi</strong></td><td>Green</td><td>This light indicates that the modem is sending a Wi-Fi signal. If the light is green, you should be able to see and connect to the Wi-Fi network.</td></tr><tr><td></td><td>Flash</td><td>If you are connected to the Wi-Fi hotspot, it will flash green to indicate data going to and from the router. If the router is connected to another Wi-Fi hotspot (Wi-Fi relay), it will also flash because it has the data flow.</td></tr><tr><td></td><td>Off</td><td>If it's off, your router no longer sends a Wi-Fi signal. You can log in to the router admin and turn on the Wi-Fi master hotspot.</td></tr><tr><td><strong>SIM1</strong>/<strong>2</strong></td><td>Green</td><td>These lights indicate which SIM card the router is using. It uses the SIM1 by default. You can change to use SIM2 on the router admin.</td></tr></tbody></table>