[t8y]

Mostly it is latency added by webcams, microphones(But our ears are used to delayed audio anyway) and the software. Your webcam probably has >100ms of latency then the app adds >50ms then multiply that by 2x (for two way conversation). Even a display like a TV can have loads of latency.

If you just open up a camera view there's huge latency without it even sending data anywhere. The internet latency is probably only a small portion of over all latency and WiFi latency isn't much either. There's already lots of latency with audio (Perhaps having a microphone could make audio travel faster then through air?)

I wish people would take latency more seriously. Using a rolling shutter, encoding a single line at a time and sending it via UDP could probably save almost all the latency. Sub 30ms latency IMO would make it much better.

[jhugo]

For distributed teams the Internet RTT between a pair of call participants is frequently higher than 300ms, and that's unloaded -- if the connection is marginal then average RTT could be much higher.

Wi-Fi is also a huge contributor to latency. In congested areas or with problematic APs or end stations it's not uncommon to see packets delayed more than 500ms by retransmits. The average might be lower, but with frequent excursions to much higher than average latency.