Networking – Device with no IP address is able to communicate with the network

ip addressnetworkingwireless-networking

I have recently purchased a WiFi infra red hub that can be used to send IR signals to various devices. This is all set up and working fine.

I looked on the router, Fing and viewed the ARP table to try to find the device's IP address, but it doesn't appear anywhere. I've also looked on the router to see if this device is listed.

So, I'm now curious, how is this device communicating with the outside world if it doesn't have an IP address?? Is it able to broadcast to an external IP address via UDP or something with only its MAC address?

The device is branded as Aigoss, and it links to the Tuya Smart Home system.

Using the Tuya app, I can operate IR devices, even when I'm not at home, so it must be connected to the network/internet somehow.

Best Answer

To answer correctly this question you have to be a bit familiar with the OSI model: Read this wikipedia page to have an introduction to the OSI model.

I think after you read the layer 2 the answer of your question will be clear:

Layer 2: Data Link Layer The data link layer provides node-to-node data transfer—a link between two directly connected nodes. It detects and possibly corrects errors that may occur in the physical layer. It defines the protocol to establish and terminate a connection between two physically connected devices. It also defines the protocol for flow control between them.

IEEE 802 divides the data link layer into two sublayers:[7]

Medium access control (MAC) layer – responsible for controlling how devices in a network gain access to a medium and permission to transmit data. Logical link control (LLC) layer – responsible for identifying and encapsulating network layer protocols, and controls error checking and frame synchronization. The MAC and LLC layers of IEEE 802 networks such as 802.3 Ethernet, 802.11 Wi-Fi, and 802.15.4 ZigBee operate at the data link layer.

The Point-to-Point Protocol (PPP) is a data link layer protocol that can operate over several different physical layers, such as synchronous and asynchronous serial lines.

The ITU-T G.hn standard, which provides high-speed local area networking over existing wires (power lines, phone lines and coaxial cables), includes a complete data link layer that provides both error correction and flow control by means of a selective-repeat sliding-window protocol.

So you can control the IR because (even is wifi or wired connected) they are in the same network and they know the mac address of each other, then communication between the device is possible without an IP address.

I hope this answer clarify your doubt.

An update, I read about from your app you can control this IR also from the outside world, this is possible only if the app on your phone connect to the Tuya Smart Home system which send the command to the IR.

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