On Mon, 2 Sep 2019 at 17:49, Marek Isalski <[email protected]> wrote: > > > On 2 Sep 2019, at 17:37, Nicholas Humfrey <[email protected]> > > wrote: > > Is there any chance of multicast making a resurgence? If everyone has > > gigabit internet to their homes, will the network cores be able to cope > > with everyone watching 35 Mbps UHD (Live) television streams simultaneously? > > Isn't it all about on-demand streaming now, rather than broad-/multi-cast? I > mean, who actually watches live TV these days? It seems like building a > network for the future of video consumption (Millenial and Gen-Z) will need > CDN-type nodes as close as possible to distribution/aggregation nodes rather > than multicast across a backbone? Maybe multicast still has a role to play > to deliver content to set-top boxes...?
This. It's costly to transport terabits of traffic from one end of your network to the other, most ISPs want to drop it off as close to the consumer as possible so in my eyes, the benefits to be had from the reduction in traffic levels due to multicast just isn't that great vs. the added complexity if you can plonk the content source on your network at the 1st hop your customers hit. Another problem with multicast is that it saves bandwidth across the parts of the network where bandwidth is cheaper. At the end of the day, bandwidth (for most ISPs) is most limited and hardest to increase in the last mile, and even if it's multicast from the source to the DSLAM/MSAN/OLT/access switch, it still needs to be replicated down every access circuit that's subscribed to the multicast group, the same as if it was unicast to each customer, so it's not saving any bandwidth in those hard to upgrade and expensive to upgrade parts of the network. It's also possible increases the cost of a "dumb" access layer device and CPE if they need to support multicast and increases the number of test case for release cycles. I'm obviously not a fan :) Cheers, James.
