On 22/03/2020 9:04 am, Tom Worthington wrote: > On 20/3/20 5:04 pm, Paul Brooks wrote: > >> Actually, videoconferencing ... I'm not convinced its a problem ... > > If most people in Australia are at home, what proportion of them can be on a > video > conference at the same time?
Local effects, gated by the capacity of each home's link and how many people in the home are on VCs simultaneously. The main effect is congestion of the local house's access line. Right now I have 3 of the 4 occupants on conference calls either audio or video quite successfully on a 50/20 link, leaving plenty of bandwidth to spare, but slower access lines may not be able to support so many simultaneously. If its one person per house, then a very large proportion of Australia could on VCs at the same time, outside peak hours - perhaps up to 30 - 40% which would be highly unlikely in practice. Secondary effects may be congestion of the POI, and the general interstate/international backbone, however most VCs are done during daytime or non-peak hours, when the POI links and backbone/backhaul links are at 50% utilisation or thereabouts. Very few videoconferences amongst the Australian population would occur during the Internet busy-hours of 8pm-10pm. Those hours are peak hours on local access lines primarily due to one-way intertainment streaming, which does auto-adjust up, and the main services have made steps to reduce their bandwidth usage by 25% or so per user. More to the point, for backhaul, longhaul and POI links, if traffic was to rise to the point that congestion was close (e.g. due to a rise in VC use from homes), capacity upgrades can occur within hours, days or at worst around 6-8 weeks if new DWDM transmission linecards are required - there is so much unused fibre lying around that can be quickly lit up that congestion in the backbone should never be apparent to the general population. You can check out the utilisation and diurnal curve of one mid-sized ISP at https://www.aussiebroadband.com.au/cvc-graphs/. Note that almost all of them, actual utilisation between 8am and 6pm is roughly 50% used, 50% idle. That 50% idle capacity can support a very large proportion of the population on VCs during those hours, without even needing augmentation of the backbones/backhauls. The best way to limit congestion of Internet infrastructure is for the entertainment streaming services to limit their usage, as they are doing described at: https://www.itnews.com.au/news/netflix-to-slash-traffic-across-europe-to-relieve-virus-strain-on-internet-providers-539668 https://www.itnews.com.au/news/youtube-amazon-prime-forgo-streaming-quality-to-relieve-european-networks-539673 Paul. _______________________________________________ Link mailing list [email protected] http://mailman.anu.edu.au/mailman/listinfo/link
