Kilobit per second to Terabit per second

Audio codecs compress sound into a stream of bits played back in real time, so the natural unit is bits per second. At 128 kbps, an MP3 encoder allocates 128,000 bits to represent each second of audio. Higher kbps means more data per second, better quality, and larger files.

Technically yes — dial-up ISPs like NetZero still exist in the US, and some rural areas with no broadband rely on them. But at 56 kbps, loading a modern webpage (average 2.5 MB) would take over 5 minutes. It is functionally unusable for anything beyond basic email.

At 128 kbps, the encoder discards more audio detail — cymbals sound washy, stereo imaging narrows, and quiet passages lose nuance. At 320 kbps, most listeners cannot distinguish the MP3 from the original CD in blind tests. The file is 2.5× larger but audibly transparent to most ears.

A standard VoIP call uses 8–64 kbps depending on the codec. The widely used Opus codec delivers excellent voice quality at 16–32 kbps. Traditional landline phone calls used 64 kbps (G.711 codec). HD Voice on modern smartphones uses about 32 kbps with the AMR-WB codec.

The screeching was the modem handshake — two modems negotiating their connection speed by exchanging test tones over the phone line. Each phase of the screech tested different frequencies and protocols. The modems were literally talking to each other in audio, finding the fastest kbps rate the line could support.

Global internet traffic peaks at roughly 1,000–1,500 Tbps (1–1.5 Pbps) as of 2026. This is growing at about 25% per year, driven by video streaming, cloud computing, and AI training data transfers. A single viral live event can spike regional traffic by tens of Tbps.

Internet traffic automatically reroutes through other cables and paths via BGP routing protocols, usually within seconds. Speed may degrade in the affected region but rarely drops entirely. Cable cuts happen more often than people think — about 100 per year globally, mostly from ship anchors and fishing trawlers.

Dense wavelength-division multiplexing (DWDM) sends dozens of different light colors (wavelengths) through a single fiber simultaneously, each carrying its own data stream. A modern cable contains multiple fiber pairs, each carrying 100+ wavelengths, with each wavelength modulated at 400 Gbps or more.

Netflix's library is estimated at around 30–40 petabytes. At 1 Tbps, downloading the entire catalog would take roughly 70–90 hours. At 100 Tbps (a realistic submarine cable capacity), you could theoretically grab all of Netflix in under an hour.

Researchers at Japan's NICT achieved 22.9 Pbps (22,900 Tbps) through a single multicore fiber in 2024. That is enough to transfer the entire Library of Congress in a fraction of a second. These lab records typically reach commercial deployment 5–10 years later.