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Netflix streaming quality - Page 80

post #2371 of 5480
Interesting! I'm curious about the technical explanation.

I can come up with two possibilities for performance differences. One is that the ISP's name server is broken and resolution is slow or even timing out entirely. The other is that the name servers are resolving names to different addresses.

Hmmm...

Is 3rd party DNS capable of providing localized addresses for name resolution of netflix's CDN? My understanding is that they don't do this.

Assuming that the ISP and 3rd party DNS are answering with different addresses, is it that the ISP supplied addresses are incorrectly localized, or that a perhaps the local portion of the CDN is performing badly? If the local netflix servers or connections to those servers are performing badly, switching to a more remote server could actually improve performance.

In general though, I think that the ISP's name servers would be preferable. But if experiencing problems, switching to 3rd party DNS is a valid workaround.

I'm certainly no expert though. So if anyone has better info, please correct or add to the above theorizing...
post #2372 of 5480
Sorry, I should have checked the "auto" DNS address but according to another post on the Sony support forum the Sony players use Sony's DNS servers and it was okay up until recently. And apparently my Samsung player was using Samsung's DNS server. Maybe this is the case with most players so that marketing can gather some statistics.
post #2373 of 5480
Quote:
Originally Posted by dfiler View Post

I'm certainly no expert though. So if anyone has better info, please correct or add to the above theorizing...

I manage several DNS servers and overall DNS resolution should have very little or no impact on performance in the general sense. It strictly resolves an address and once that's accomplished it no longer plays any part in the process. Such as...

You look in a phone book for the address of Netflix. Once you know the address the phone book is no longer involved. Regardless of how you interact with Netflix (the number of trips or how you travel there). The only time DNS would come back into play is when that address needs to be updated. Which can lead into a tricky path of technical details... although the process will typically have no reason to look the address up again.

If you want to go down that technical path all DNS servers should reflect the same information (varied by refresh intervals). Sure one might take a touch longer than another to resolve an address but that's a one time deal... not involved in the streaming process itself. It just provides the address so the parties know where they are located.

Now all of the above is completely non technical and only presented as bad examples that hopefully make some sense. Obviously, if you can't find the phone book or if it contains bad information it could be an issue. However that would result in not providing you with the address so you would never get started (on your trip).
post #2374 of 5480
The OpenDNS thing is interesting. I'm going to try it, because streaming quality through TW-Cable on my Sony BDP is terrible and glitchy, with lots of buffering failures, and due to Cinavia paranoia I'd prefer to never update its firmware again.

@Charles: my understanding is that netflix's code somehow uses the DNS set in the client (whether static or by DHCP from upstream) to determine which ISP you're on and where, and so which content distribution server you stream from. Not sure what that would mean in terms of OpenDNS's topology. Maybe that just means NF makes fewer assumptions about what you're service is and can and can't handle (or how much data an ISP will quietly accept Netflix plowing through their network before they start threatening them with traffic shaping.)
post #2375 of 5480
Quote:
Originally Posted by innatetech View Post

@Charles: my understanding is that netflix's code somehow uses the DNS set in the client (whether static or by DHCP from upstream) to determine which ISP you're on and where, and so which content distribution server you stream from.

Physical location means very little regarding the Internet. And if they wanted to guess your location... I don't understand why they wouldn't use more accurate data such as your account information. Also, someone like AT&T publishes two DNS addresses for the entire country.

Of course they could take a guess at your location but what real value does it provide? Streaming issues would be much more related to their servers, their (initial) pipeline, your (ending) pipeline all of which are fixed. The key to my thinking is balancing traffic load at their servers and their initial pipeline. Managing their resources as best as possible would have virtually nothing to do with your location. Rather controlling what's going on at their various locations.

I would expect them to employ load balancing. Again, not a technical overview rather a bad example...
http://en.wikipedia.org/wiki/Load_balancing_(computing)
post #2376 of 5480
Wouldn't it be more useful to know the IP addresses of the various Netflix servers and then do a traceroute to discover where the problem is in the path? I can't see where changing to OpenDNS or GoogleDNS is really going to make a difference unless you have a wretched internet provider. If there is a problem often it will lie with the device, router and/or modem. Or even the line that runs from your home to the pole and beyond.
post #2377 of 5480
Quote:
Originally Posted by Charles R View Post

Physical location means very little regarding the Internet. And if they wanted to guess your location... I don't understand why they wouldn't use more accurate data such as your account information. Also, someone like AT&T publishes two DNS addresses for the entire country.

Of course they could take a guess at your location but what real value does it provide? Streaming issues would be much more related to their servers, their (initial) pipeline, your (ending) pipeline all of which are fixed. The key to my thinking is balancing traffic load at their servers and their initial pipeline. Managing their resources as best as possible would have virtually nothing to do with your location. Rather controlling what's going on at their various locations.

I would expect them to employ load balancing. Again, not a technical overview rather a bad example...
http://en.wikipedia.org/wiki/Load_balancing_(computing)

I'm familiar with load balancing, round robin DNS, etc. I'm just relaying what I've heard about what changing DNS is supposed to do in re Netflix, I'm not saying it makes a ton of sense.

If I had to guess as to whys, maybe because they have various CDSes that are within the peering agreements of various ISPs? It's not physical location so much as network location. Or it could just be a lot of superstition and placebo effect.
post #2378 of 5480
Quote:
Originally Posted by innatetech View Post

I'm familiar with load balancing, round robin DNS, etc. I'm just relaying what I've heard about what changing DNS is supposed to do in re Netflix, I'm not saying it makes a ton of sense.

I'm not saying you're wrong. Just my take is it's more Urban Legend as in I have never read (I don't read a lot ) any articles addressing such.

Quote:


If I had to guess as to whys, maybe because they have various CDSes that are within the peering agreements of various ISPs? It's not physical location so much as network location. Or it could just be a lot of superstition and placebo effect.

The only real advantage I can see (at least off the top of my head) is if Netflix knew the customer's actual location (network not physical) if it's available they could stream within the same network and never hit the Internet per se. Which really only favors the network provider (less bandwidth required to the Internet) and since based on what I know everyone carries Netflix for free why would they care. As in it doesn't guarantee performance would be better.

A while back providers were looking to ding Netflix for their traffic... haven't heard any more about it for a long time.
post #2379 of 5480
Quote:
Originally Posted by Charles R View Post

I'm not saying you're wrong. Just my take is it's more Urban Legend as in I have never read (I don't read a lot ) any articles addressing such.

The only real advantage I can see (at least off the top of my head) is if Netflix knew the customer's actual location (network not physical) if it's available they could stream within the same network and never hit the Internet per se. Which really only favors the network provider (less bandwidth required to the Internet) and since based on what I know everyone carries Netflix for free why would they care. As in it doesn't guarantee performance would be better.

A while back providers were looking to ding Netflix for their traffic... haven't heard any more about it for a long time.

It might be that Netflix wants to avoid peering charges to anyone's ISP--the users ISP, or the ISP that their CDS is on (although if they do use S3 as people say, I'm not sure that makes sense.)

I also wouldn't be surprised to find that traffic that travels entirely within one major ISP's network is more rapidly delivered than traffic that must pass through peering points, which are often bottlenecks.

Still, I'm not sure how confusing their optimization scheme would improve performance, unless Netflix really does enter into ISP specific traffic shaping deals they don't talk about, or does so voluntarily to keep the heat off (making it something other than "optimization" from the user's standpoint.) That could be why the saber-rattling has ceased...
post #2380 of 5480
The bottom line is that before I manually changed the DNS it would take on average 5 minutes for the Sony player connect to Netflix and occasionally 20 minutes of retries. That's ridiculous and something I never experienced with the Samsung player. I was ready to return the player as damaged but research turned up the manual DNS setting. No waits now. Sorry if it confounds the IT techs here.
post #2381 of 5480
Are some Netflix HD movies streamed in 1080p and some in 720p? Is there a listing somewhere showing this? Thanks.
post #2382 of 5480
Quote:
Originally Posted by Charles R View Post

I'm not saying you're wrong. Just my take is it's more Urban Legend as in I have never read (I don't read a lot ) any articles addressing such.

The only real advantage I can see (at least off the top of my head) is if Netflix knew the customer's actual location (network not physical) if it's available they could stream within the same network and never hit the Internet per se. Which really only favors the network provider (less bandwidth required to the Internet) and since based on what I know everyone carries Netflix for free why would they care. As in it doesn't guarantee performance would be better.

A while back providers were looking to ding Netflix for their traffic... haven't heard any more about it for a long time.

I too manage dns servers so it isn't like I'm speculating about what is technically possible. Instead I'm uncertain of exactly which strategy is being used.

The choice of name server can effect performance of name resolution, but that isn't what is important here. What is of importance is connecting to the optimal segment of the cdn. They tend to be physically distributed across continents so best performance is typically achieved by streaming from the closest farm of servers. More accurately, the servers with the lowest latency. DNS can and is used to achieve is for many web services. The same name will resolve to different addresses for someone in Pittsburgh vs someone in Berlin.

However I'm not sure if that is what Netflix is doing. They could also determine your ISP and location by looking at which name server is being used. It is then possible to choose servers co-located within the ISP's network or one with the best peering arrangement.

Another optimization strategy would be to dynamically analyze performance to alternative servers, looking at larency, the number of hops, and which networks those hops land on. This wouldn't be dependent on dns at all.

The only thing I'm sure of is that name resolution performance isn't the performance that matters. Once connected and streaming, there isn't any name resolution happening.
post #2383 of 5480
Quote:
Originally Posted by Jim McC View Post

Are some Netflix HD movies streamed in 1080p and some in 720p? Is there a listing somewhere showing this? Thanks.

I believe that the great majority of Netflix streaming titles have available 1080p encodings. I went though 30 HD titles at random once and all of them had 1080p encodings. Others have pointed out the occasional title limited to 720p (Scary Movie was one and a few seasons of some anime series where other seasons of the same series had 1080p encodings). My guess is that, when they add a title that they're allowed to offer in HD, they automatically create a 1080p encoding unless the content provider specifically forbids it.

Now, 5.1 sound is relatively rare, available on about 20-25% of HD titles (I think that there are only 2 SD-only titles with 5.1 sound).
post #2384 of 5480
Quote:
Originally Posted by Jim McC View Post

Are some Netflix HD movies streamed in 1080p and some in 720p? Is there a listing somewhere showing this? Thanks.

See michaelscott's answer above, but one thing he didn't mention is you do have to have a device that gets the 1080p streams, or you're stuck with 720p. I know the PS3 and Roku 2 get 1080p, and a couple of others. But the vast majority of devices only get the 720p streams.

They really need to start pushing that capability out to everyone. I know there's a world of difference between Netflix on my XBOX 360 (720p) and my PS3 (1080p).

I don't know about the 5.1 sound or how popular it is. Michaelscott says 20-25% of titles, so he's probably right. My queue (50+ titles at the moment) is 100% HD and about 50% of those are 5.1. I don't even have an SD title in my queue at the moment, so I'm thinking they're really getting better at getting HD material.
post #2385 of 5480
Quote:
Originally Posted by dfiler View Post

What is of importance is connecting to the optimal segment of the cdn. They tend to be physically distributed across continents so best performance is typically achieved by streaming from the closest farm of servers. More accurately, the servers with the lowest latency.

Remember they have different servers for different brands of streamers so they are being directed accordingly (intelligently). Which tells me there is a lot going on in the background... before one starts actual streaming. Regarding performance I think location has very little do with it. My guess is rather the source's servers and their bandwidth ability.

Quote:


DNS can and is used to achieve is for many web services. The same name will resolve to different addresses for someone in Pittsburgh vs someone in Berlin.

They shouldn't. Location is irrelevant.

Quote:


They could also determine your ISP and location by looking at which name server is being used. It is then possible to choose servers co-located within the ISP's network or one with the best peering arrangement.

Again your DNS server says very little (or nothing) about your location. They could use your IP address and do a lookup on that... now what would be a much better guess.
post #2386 of 5480
I've heard that before, but intuitively different servers for different devices doesn't make any sense whatsoever. I'd love a formal statement about this by Netflix engineering.
post #2387 of 5480
Quote:
Originally Posted by michaeltscott View Post

I've heard that before, but intuitively different servers for different devices doesn't make any sense whatsoever. I'd love a formal statement about this by Netflix engineering.

I'm going by two level 2 support guys. When my TiVo wouldn't play something and another player would I worked with them and they routed me (the TiVo) to several servers during the testing. They also stated the other player was using a different encode/server. Of course I didn't install their network... but both were somewhat versed in the topic.

I think the real point is there is a lot going on... above and beyond a simple DNS lookup, connecting to the server and start streaming. Agreed it's 99% a mystery and one they have no interest in solving.
post #2388 of 5480
Quote:
Originally Posted by mproper View Post

See michaelscott's answer above, but one thing he didn't mention is you do have to have a device that gets the 1080p streams, or you're stuck with 720p. I know the PS3 and Roku 2 get 1080p, and a couple of others. But the vast majority of devices only get the 720p streams.

Thanks. I know I have to have a 1080p capable device. I'm hoping the new Panny players will stream in 1080p.
post #2389 of 5480
Quote:
Originally Posted by Charles R View Post

They also stated the other player was using a different encode/server.

I can absolutely believe that. TiVo is using a set of VC-1 w/WMA sound encodings, which the Xbox was also using. I believe that most of the other players switched to a set of AVC encodings (possibly with DD2.0 sound) which appeared with the PS3 disc-based player. Since the Xbox player has now switched to the AVC encodings, TiVo is the only player that I have which is still using those. (The bandwidth consumption graphs that I collected with the firmware in my router for TiVo and Xbox were peak-for-peak aligned and different from everything else (PS3, Roku, BDT110 and this PC)).
post #2390 of 5480
Quote:
Originally Posted by Charles R View Post

Remember they have different servers for different brands of streamers so they are being directed accordingly (intelligently). Which tells me there is a lot going on in the background... before one starts actual streaming. Regarding performance I think location has very little do with it. My guess is rather the source's servers and their bandwidth ability.

They shouldn't. Location is irrelevant.

Again your DNS server says very little (or nothing) about your location. They could use your IP address and do a lookup on that... now what would be a much better guess.

Location most certainly does have an affect on performance. That's one of the primary reasons for the existence of CDNs in the first place. Otherwise there would just be CDS, content distribution sites.

Here's a map of Level3, although i'm not sure how recent it is. http://www.dogado.de/fileadmin/user_...L3_cdn_map.pdf

In the same way that L3's network is distributed, so are name servers for large ISPs. I don't know if it is being used that way, but the IP of a name server could be used to roughly determine where the ISP's client is on the internet. Note that IP address based location detection is quite common. Google uses it for it's web based maps and wifi locator apps are relatively popular with mobile users.

Granted, I don't think netflix is using your DNS IP for determining your network location. Rather I was just thinking through all the possibilities for why choice of name server can affect streaming performance.

The real reason is a trade secret that likely won't be divulged by any of the corporations involved. They like to be tightlipped about the proprietary technology running these networks.
post #2391 of 5480
Quote:
Originally Posted by dfiler View Post

Location most certainly does have an affect on performance.

Some affect sure although one of the smallest factors. I stated location is irrelevant regarding a DNS lookup. No matter where you are you should resolve to the same address. I can guarantee a server getting hammered (or its local bandwidth) is going to be multiple times slower even if it's located a few feet away than an idle one located thousands of miles away. As covered a while back it's mostly about load balancing their servers... traffic and available (local) bandwidth. I'm sure this load balancing involves placing traffic at various locations. I simply think it's balanced based on Netflix's load (their servers and available bandwidth).

Quote:


I don't know if it is being used that way, but the IP of a name server could be used to roughly determine where the ISP's client is on the internet.

Many National/Global companies use one DNS server address so again there is no tie into your address. If you wanted to know where one is located why wouldn't you use their IP address?
post #2392 of 5480
Quote:
Originally Posted by msgohan View Post

The service I use to access US video streamers including Netflix and Vudu works by just changing the DNS servers on my router/streamer to the addresses they provide. No idea how it works on their end, but simply using their DNS addresses is enough to get around the country lockout and then the actual video traffic is passed directly. On the other hand, using any old US DNS doesn't work.

Did you have to change the router's Gateway? Or did you only change DNS entries? I don't see how only changing DNS would work but then again I don't provide such services. Obviously it shows Netflix doesn't base your location on your DNS entries.

This link is related... covering how they either hide/change your local IP address... nothing to do with DNS.

http://www.thereviewcrew.com/news/ho...of-usvideo-ca/

Netflix tracks its users’ IP address to see which service you get access to. If you live in Canada and have a Canadian IP address, you automatically get the limited Canadian Netflix service.

USVideo makes it clear it is not a VPN (Virtual Private Network service). It tricks Netflix into thinking you are in the United States by making a few changes to settings in your router.

Now that your IP is hidden you, can access Netflix.com rather than automatically be taken to Netflix.ca.

Of course with a VPN your IP address would/could become US.
post #2393 of 5480
Quote:
Originally Posted by msgohan View Post

Never had to change Gateway. It's currently shown as 0.0.0.0 in my dd-wrt settings.

Clearly it's not DNS related. And since this topic is rather taboo and DNS is pretty much off topic for the thread itself I'll drop both.
post #2394 of 5480
Interesting example probably of network congestion or demand on Netflix was I selected an HD movie in my queue at 8:59 PM last night and the bitrate indicator showed the connection had difficulty getting over 1 mbps and the resulting video was like a 160 line image blown up to 1080. So I stopped, checked my network speed which was around 5 mbps then went back to try the movie at 9:10 PM and it played all the way through in HD.
post #2395 of 5480
Really weird thing tonight with the ps3. My titles start autoscrolling to the right in the menu until they get to the last title and I can't stop it. In each category. I deleted the app and reinstalled. Still happening
post #2396 of 5480
On DNS changes and improvements to performance, I thought companies like Akamai would seed different DNS's with different IPs, assuming that you're 'close' (in network terms) to the DNS you're using. The DNS would resolve and send you to the edge server most optimal to that DNS - which in many cases would be most optimal for the end user.

If that's the case, then changing DNS's could result in using a completely different edge server and a completely different route to access it. Pointing to a different edge server could improve performance if the path to the supposed 'optimal' one is poor.

Personally, I have less issue resolving than I do maintaining performance after resolution. I can stream several HD shows in a row with no issue, then hit a period of 'rebuffering' and reduced quality - despite no change in DNS, network utilization on my side, or speedtest/ping results. Amazon is worse for this than Netfilx for me.
post #2397 of 5480
So is the only thing we can do with Netflix films that have partial or cut-off subtitles is to report it as a problem to them? Couldn't find any answer after searching the thread. Curious if I'm missing something I can be doing, though no matter what mode I switch to, certain parts of the subtitles are cut-off.
post #2398 of 5480
Quote:
Originally Posted by technikal View Post

On DNS changes and improvements to performance, I thought companies like Akamai would seed different DNS's with different IPs, assuming that you're 'close' (in network terms) to the DNS you're using. The DNS would resolve and send you to the edge server most optimal to that DNS - which in many cases would be most optimal for the end user.

If that's the case, then changing DNS's could result in using a completely different edge server and a completely different route to access it. Pointing to a different edge server could improve performance if the path to the supposed 'optimal' one is poor.

Once again directing traffic to a server whether it be within a few feet or thousands of miles away via some DNS voodoo offers very little (if any) guarantee it's best suited to handle the task. Take this simple very non technical example...
  • You have two servers. One in New York City and one in Nome, Alaska.
  • Netflix currently has one thousand users in New York that want to stream Mad Men
  • Do you expect the best performance would be obtained by routing all one thousand customers to the New York City server?
  • My guess is the server and its local (available) bandwidth would be hammered. Performance would be much improved by load balancing (50/50) the traffic between the two servers. The advantage you gain by locality is negligible compared to most any other factor.
I might be giving them too much credit but I can't believe they don't have some type of load balancing implemented and a pure guess is hitting your closest server isn't a majority factor. And if it is once again your IP address is x times better for guessing your location.
post #2399 of 5480
Quote:
Originally Posted by subavision212 View Post

So is the only thing we can do with Netflix films that have partial or cut-off subtitles is to report it as a problem to them? Couldn't find any answer after searching the thread. Curious if I'm missing something I can be doing, though no matter what mode I switch to, certain parts of the subtitles are cut-off.

What title are you viewing and what are you viewing it with?
post #2400 of 5480
What most people do is mention things like titles cut off or incorrect aspect ration like showing 3:2 squeezed image instead of it being stretched to 16:9 is to write a review mentioning it. I've found two titles with the squeezed image and people already had mentioned it in the reviews and one Asian title where the subtitles were cut off even viewing the full image on a computer. There doesn't seem to be much QA at Netflix about streams though there are only enough new ones released every week to give one person a full or part time jobs just running each title for a few minutes.
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