Technical Support

First, it’s important to distinguish between bits and bytes. 1 byte = 8 bits, 1 kilobyte = 8 kilobits. Providers usually specify the speed in bits, and this is generally accepted. However, many programs display the download speed in bytes. In your case, everything is correct; we divide 128 kilobits by 8 and get 16 kilobytes. However, providers usually provide a slightly lower speed than they promise, so 15/30 is a perfectly normal value.

however, it only becomes that way late at night and until early morning!!

What is the speed at other times of the day? Perhaps the tariff plan is such that the speed doubles at night...