RX and TX speeds refer to the data transfer rates for a network connection, typically measured at a specific point, such as a wireless access point (AP) when communicating with a client device. They represent the speed at which data is moving in opposite directions.
RX Speed: This is the receive speed at the point of measurement. For example, if you're looking at the RX speed reported by an AP for a connected client, it indicates how fast the AP is receiving data from that client.
TX Speed: This is the transmit speed at the point of measurement. If you're looking at the TX speed reported by an AP for a connected client, it indicates how fast the AP is sending data to that client.
Think of it from the perspective of the device reporting the speed.
Understanding RX and TX in Practice
As highlighted in the community.ui.com reference, systems like the Unifi controller report TX and RX for each client at the AP.
- TX at the AP: This is the speed the AP uses to send data to the client.
- RX at the AP: This is the speed the AP uses to receive data from the client.
The reference provides a clear example: "if it says Rx 500, Tx 900, then that means that this AP can send to this client at 900Mbps and receive from it at 500Mbps."
TX vs RX: A Quick Comparison
Here's a simple breakdown:
| Feature | RX (Receive) Speed | TX (Transmit) Speed |
|---|---|---|
| Direction | Data coming into the measurement point (e.g., the AP) | Data going out from the measurement point (e.g., the AP) |
| From AP to Client | Represents the speed the AP receives from the client | Represents the speed the AP sends to the client |
| Common Scenario | Often relates to upload speed from the client's perspective | Often relates to download speed from the client's perspective |
It's important to note that while TX (AP) corresponds to client download and RX (AP) corresponds to client upload, the reported speeds are the link rates or negotiated connection speeds between the devices, which can be higher than the actual data throughput achieved due to overhead and other factors.
These rates can differ for a single client due to various factors, including:
- Client device capabilities
- Distance from the AP
- Interference
- Specific Wi-Fi standards and technologies supported by both devices
Understanding RX and TX speeds is key to diagnosing network performance issues and understanding the potential capacity of a wireless link from the perspective of the AP.
