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Netflix takes up 9.5% of upstream traffic on the North American Internet

arstechnica.com

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Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#11

Post by redbeard0x0a »

cperciva wrote: post #6

From the article: the newest report has Netflix at 9.48 percent of upstream and 34.89 percent of downstream [...] The average Internet subscribing household in North America uploaded 7.6GB of data per month in Sandvine's report in the first half of this year, increasing to 8.5GB in the latest report, a boost of 11.8 percent. The average household's monthly downloads increased from 43.8GB to 48.9GB, a boost of 11.6 pe…

Don't forget the retransmissions due to the under-provisioned links to Level3 networks by some companies who are currently (or have in the past) extorted money out of Netflix.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#12

Post by lttlrck »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

Every site streaming HTML5 video is using TCP including YouTube. Traffic engineering appears to have reduced the argument for UDP for media in recent years, which is a good thing!

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#14

Post by cjensen »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

TCP deals with congestion and bandwidth allocation automatically. Decades of algorithms work in your favor if you use TCP.

A single missing packet will seriously mess up your video stream. Remember that long sequences of movie pictures are sent as a single whole image plus delta instructions to generate the rest of the images. A single bad packet can screw up a second of video.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#15

Post by rustyconover »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

A few missing packets may not matter, you're right. MPEG has a lot of error checking and error handling built into the transport stream layer.

But I think the bigger reason Netflix uses TCP is because TCP has a much easier time with NAT traversal and not needing port forwarding. By looking and acting like normal web traffic it makes it easier to guarantee that things will just work rather than need any special accommodation.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#16

Post by dlubarov »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

Compressed video formats like H.264 rely on frames arriving in order. Most frames are described as a diff relative to one of the 16 previous frames.

You could devise a format that tolerates loss better, but the quality and/or compression ratio wouldn't be as good.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#17

Post by rustyconover »

cjensen wrote: post #14
ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

TCP deals with congestion and bandwidth allocation automatically. Decades of algorithms work in your favor if you use TCP. A single missing packet will seriously mess up your video stream. Remember that long sequences of movie pictures are sent as a single whole image plus delta instructions to generate the rest of the images. A single bad packet can screw up a second of video.

Depending on the rate of keyframes in the stream, it could be from anywhere from 3 to 10 seconds. And if the GOP[1] is even larger it could be longer.

[1] - http://en.wikipedia.org/wiki/Group_of_pictures

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#18

Post by jkarneges »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

TCP is more efficient than UDP if you don't need low-latency delivery, because you can compress more data at once and waiting for retransmitted packets isn't a problem. This also ensures you get a high quality stream through the viewing experience unless there are major congestion problems.

A video chat will always prefer UDP transmission for the lowest latency possible, but quality may vary and bandwidth usage can technically be higher.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#19

Post by drawkbox »

Netflix doesn't take it up, paying broadband customers are all requesting individual content that happens to be at Netflix due to the customer benefits.

Netflix just has some files on a server and streams content. Netflix isn't broadcasting but customers are pulling that content. The consumers/customers of Netflix take up 9.5% upstream, granted improvements can probably be made in their software.

There is a disparity how online entities are seen as bad due to taking too much interest from customers where TV numbers don't include bandwidth usage over broadband or spectrum usage and having x number of viewers is seen as good.

This just means Netflix is a popular and big channel or land of content that people spend lots of time in as paying broadband customers using their bandwidth and content customers paying Netflix for access to content. So this can't really be used to justify broadband companies lobbying.

There does need to be improvements to broadcasting on the web which was explored with multicast and maybe SCTP will be more interesting soon as that could help with the TCP problems.

Re: Netflix takes up 9.5% of upstream traffic on the North American Internet

#20

Post by wmf »

ams6110 wrote: post #9

Why does Netflix use TCP for streaming instead of UDP? A few missing packets isn't going to meaningfully impact a video stream.

There's a good explanation in http://www.dtc.umn.edu/~odlyzko/doc/net.neutrality.delusions... (2008) section 3 which explains "why faster-than-real-time progressive downloads of music or video are far preferable to real-time streaming. But first let us consider the strange situation in which this issue is not discussed publicly, and the advocates of each of the two types of video transmission mostly seem unaware there is a real alternative to their preferred solution, and that there is a serious decision that has to be made for each video service."
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