The upload speed stands for the direction of data transmission from you to the Internet. In connection with the data speed of this transmission direction, the upload parameter is accompanied by b/s as the basic unit, while more often you can see Mbps (megabites per second), or Gbps (gigabites per second). The resulting upload speed which is part of the result of your test carried out by the CTU NetTest measurement tool is the actually achieved speed in the given measurement interval. For carrying out one test by the NetTest tool, it is 10 seconds. This actually achieved speed characterises the real performance of Internet access service (IAS).
The upload speed is often advertised with significantly lower value than the download speed. Nevertheless, the upload speed is very important as the communication via TCP protocol on the Internet happens in both directions (the successfully downloaded data are being continuously confirmed and vice versa). The upload speed is particularly important e.g. for sending photos, sharing files, or for videoconferencing.
It is important to notice that the download speed value corresponds to the transport layer of your IAS (the Internet connection) using the TCP protocol, i.e. the most often used transport layer protocol, from the end user’s point of view. The upload speed value should be in the range of values of the maximum speed and the normally available speed for most of the day (95 % of daytime). These values can be found in your contractual conditions (e.g. in the contract on the provision of IAS, in Terms and Conditions, or in Price list, etc.). The upload speed can decrease below the value of the normally available speed for a short time, but not in such a way that this decrease would cause appearance of significant discrepancies or even service outage. Service outage means a situation when the upload speed decreases under the maximum speed value as stated in contractual conditions. In these cases, you can apply your right to submit a claim against a defective service provision to your IAS provider.