I have seen a lot of questions about what is needed for 
video/eLearning/telehealth. IMO the beauty of those apps is that they use 
adaptive bitrate protocols and can work in a wide range of last mile 
environments – even quite acceptably via mobile network while you are in 
transit. In my experience most of the challenges people experience are due to 
home LAN (especially WiFi) issues, with working latency an underlying issue 
(aka latency under load).

Some recent papers from NetForecast on video conferencing 
(https://www.netforecast.com/wp-content/uploads/NFR5137-Videoconferencing_Internet_Requirements.pdf)
 and eLearning 
(https://www.netforecast.com/wp-content/uploads/NFR5141-eLearning-Bandwidth-Requirements.Final_.pdf)
 were based on observed actual usage rather than theoreticals. What caught my 
eye was their unique focus in the 1st paper in Figure 8 – laying out the 
rationale for a network “latency budget”. In essence, after 580 ms of delay 
someone will notice audio delay and feel the session is bad. A conference 
platform’s clients & servers may use up 300 ms of their own in processing, 
leaving about 280 ms for the network. If you working latency starts to exceed 
that on the LAN (not uncommon) then user QoE degrades.

JL

Reply via email to