From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sainfoin-smtp-out.extra.cea.fr (sainfoin-smtp-out.extra.cea.fr [132.167.192.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 0A7A13B2A4 for ; Sat, 16 Mar 2024 13:21:49 -0400 (EDT) Received: from pisaure.intra.cea.fr (pisaure.intra.cea.fr [132.166.88.21]) by sainfoin-sys.extra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 42GHLniX029980 for ; Sat, 16 Mar 2024 18:21:49 +0100 Received: from pisaure.intra.cea.fr (localhost [127.0.0.1]) by localhost (Postfix) with SMTP id 05CD9205CB7 for ; Sat, 16 Mar 2024 18:21:49 +0100 (CET) Received: from muguet1-smtp-out.intra.cea.fr (muguet1-smtp-out.intra.cea.fr [132.166.192.12]) by pisaure.intra.cea.fr (Postfix) with ESMTP id F2D4F205CB1 for ; Sat, 16 Mar 2024 18:21:48 +0100 (CET) Received: from [10.11.240.36] ([10.11.240.36]) by muguet1-sys.intra.cea.fr (8.14.7/8.14.7/CEAnet-Internet-out-4.0) with ESMTP id 42GHLmPF043933 for ; Sat, 16 Mar 2024 18:21:48 +0100 Message-ID: Date: Sat, 16 Mar 2024 18:21:48 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: fr To: starlink@lists.bufferbloat.net References: <5CA23B3B-B3FB-4749-97BD-05D3A4552453@gmail.com> From: Alexandre Petrescu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CEA-Virus: SOPHOS_SAVI_ERROR_OLD_VIRUS_DATA Subject: Re: [Starlink] =?utf-8?q?It=E2=80=99s_the_Latency=2C_FCC?= X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 16 Mar 2024 17:21:50 -0000 I retract the message, sorry, it is true that some teleoperation and visioconf also use 4K. So the latency is important there too. A visioconf with 8K and 3D 16K might need latency reqs too. Le 16/03/2024 à 18:18, Alexandre Petrescu via Starlink a écrit : > > Le 15/03/2024 à 21:31, Colin_Higbie via Starlink a écrit : >> Spencer, great point. We certainly see that with RAM, CPU, and >> graphics power that the software just grows to fill up the space. I >> do think that there are still enough users with bandwidth constraints >> (millions of users limited to DSL and 7Mbps DL speeds) that it >> provides some pressure against streaming and other services requiring >> huge swaths of data for basic functions, but, to your point, if there >> were a mandate that everyone would have 100Mbps connection, I agree >> that would then quickly become saturated so everyone would need more. >> >> Fortunately, the video compression codecs have improved dramatically >> over the past couple of decades from MPEG-1 to MPEG-2 to H.264 to VP9 >> and H.265. There's still room for further improvements, but I think >> we're probably getting to a point of diminishing returns on further >> compression improvements. Even with further improvements, I don't >> think we'll see bandwidth needs drop so much as improved quality at >> the same bandwidth, but this does offset the natural >> bloat-to-fill-available-capacity movement we see. > > I think the 4K-latency discussion is a bit difficult, regardless of > how great the codecs are. > > For one, 4K can be considered outdated for those who look forward to > 8K and why not 16K; so we should forget 4K.  8K is delivered from > space already by a japanese provider, but not on IP.  So, if we > discuss TV resolutions we should look at these (8K, 16K, and why not > 3D 16K for ever more strength testing). > > Second, 4K etc. are for TV.  In TV the latency is rarely if ever an > issue.  There are some rare cases where latency is very important in > TV (I could think of betting in sports, time synch of clocks) but they > dont look at such low latency as in our typical visioconference or > remote surgery or group music playing use-cases on Internet starlink. > > So, I dont know how much 4K, 8K, 16K might be imposing any new latency > requirement on starlink. > > Alex > >> >> >> -----Original Message----- >> From: Spencer Sevilla >> Sent: Friday, March 15, 2024 3:54 PM >> To: Colin_Higbie >> Cc: Dave Taht via Starlink >> Subject: Re: [Starlink] It’s the Latency, FCC >> >> Your comment about 4k HDR TVs got me thinking about the bandwidth >> “arms race” between infrastructure and its clients. It’s a particular >> pet peeve of mine that as any resource (bandwidth in this case, but >> the same can be said for memory) becomes more plentiful, software >> engineers respond by wasting it until it’s scarce enough to require >> optimization again. Feels like an awkward kind of malthusian >> inflation that ends up forcing us to buy newer/faster/better devices >> to perform the same basic functions, which haven’t changed almost at >> all. >> >> I completely agree that no one “needs” 4K UHDR, but when we say this >> I think we generally mean as opposed to a slightly lower codec, like >> regular HDR or 1080p. In practice, I’d be willing to bet that there’s >> at least one poorly programmed TV out there that doesn’t downgrade >> well or at all, so the tradeoff becomes "4K UHDR or endless >> stuttering/buffering.” Under this (totally unnecessarily forced upon >> us!) paradigm, 4K UHDR feels a lot more necessary, or we’ve otherwise >> arms raced ourselves into a TV that can’t really stream anything. A >> technical downgrade from literally the 1960s. >> >> See also: The endless march of “smart appliances” and TVs/gaming >> systems that require endless humongous software updates. My stove >> requires natural gas and 120VAC, and I like it that way. Other stoves >> require… how many Mbps to function regularly? Other food for thought, >> I wonder how increasing minimum broadband speed requirements across >> the country will encourage or discourage this behavior among network >> engineers. I sincerely don’t look forward to a future in which we all >> require 10Gbps to the house but can’t do much with it cause it’s all >> taken up by lightbulb software updates every evening /rant. >> >>> On Mar 15, 2024, at 11:41, Colin_Higbie via Starlink >>> wrote: >>> >>>> I have now been trying to break the common conflation that download >>>> "speed" >>>> means anything at all for day to day, minute to minute, second to >>>> second, use, once you crack 10mbit, now, for over 14 years. Am I >>>> succeeding? I lost the 25/10 battle, and keep pointing at really >>>> terrible latency under load and wifi weirdnesses for many existing >>>> 100/20 services today. >>> While I completely agree that latency has bigger impact on how >>> responsive the Internet feels to use, I do think that 10Mbit is too >>> low for some standard applications regardless of latency: with the >>> more recent availability of 4K and higher streaming, that does >>> require a higher minimum bandwidth to work at all. One could argue >>> that no one NEEDS 4K streaming, but many families would view this as >>> an important part of what they do with their Internet (Starlink >>> makes this reliably possible at our farmhouse). 4K HDR-supporting >>> TV's are among the most popular TVs being purchased in the U.S. >>> today. Netflix, Amazon, Max, Disney and other streaming services >>> provide a substantial portion of 4K HDR content. >>> >>> So, I agree that 25/10 is sufficient, for up to 4k HDR streaming. >>> 100/20 would provide plenty of bandwidth for multiple concurrent 4K >>> users or a 1-2 8K streams. >>> >>> For me, not claiming any special expertise on market needs, just my >>> own personal assessment on what typical families will need and care >>> about: >>> >>> Latency: below 50ms under load always feels good except for some >>> intensive gaming (I don't see any benefit to getting loaded latency >>> further below ~20ms for typical applications, with an exception for >>> cloud-based gaming that benefits with lower latency all the way down >>> to about 5ms for young, really fast players, the rest of us won't be >>> able to tell the difference) >>> >>> Download Bandwidth: 10Mbps good enough if not doing UHD video >>> streaming >>> >>> Download Bandwidth: 25 - 100Mbps if doing UHD video streaming, >>> depending on # of streams or if wanting to be ready for 8k >>> >>> Upload Bandwidth: 10Mbps good enough for quality video conferencing, >>> higher only needed for multiple concurrent outbound streams >>> >>> So, for example (and ignoring upload for this), I would rather have >>> latency at 50ms (under load) and DL bandwidth of 25Mbps than latency >>> of 1ms with a max bandwidth of 10Mbps, because the super-low latency >>> doesn't solve the problem with insufficient bandwidth to watch 4K >>> HDR content. But, I'd also rather have latency of 20ms with 100Mbps >>> DL, then latency that exceeds 100ms under load with 1Gbps DL >>> bandwidth. I think the important thing is to reach "good enough" on >>> both, not just excel at one while falling short of "good enough" on >>> the other. >>> >>> Note that Starlink handles all of this well, including kids watching >>> YouTube while my wife and I watch 4K UHD Netflix, except the upload >>> speed occasionally tops at under 3Mbps for me, causing quality >>> degradation for outbound video calls (or used to, it seems to have >>> gotten better in recent months – no problems since sometime in 2023). >>> >>> Cheers, >>> Colin >>> >>> _______________________________________________ >>> Starlink mailing list >>> Starlink@lists.bufferbloat.net >>> https://lists.bufferbloat.net/listinfo/starlink >> _______________________________________________ >> Starlink mailing list >> Starlink@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/starlink > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink