What might happen if a customer's network has a data throughput of 6 megabits per second while streaming three HD TV data streams of 12 Mbps each?

When a customer's network has a data throughput of 6 megabits per second and they are attempting to stream three high-definition TV streams that each require 12 megabits per second, the total required bandwidth is 36 megabits per second (12 Mbps x 3). This demand drastically exceeds the available throughput of 6 Mbps.

As a result, the network cannot efficiently allocate enough bandwidth for any of the streams, leading to visual issues due to buffering and interruptions. The high-definition streams need a stable and sufficient connection to function properly, and since the available bandwidth is significantly less than what is required, all streams will experience degraded quality and performance. Buffering occurs because the data cannot be downloaded quickly enough to maintain smooth playback, which can also cause visual artifacts and interruptions in the audio-visual experience.

Thus, under these conditions, all streams would suffer from buffering and visual issues.