How is live video streamed on the internet? Since live/streaming video of course cannot be a single file. So how? Is it sent in small pieces or does data constantly flow from the source to the viewer? If so, how large is each piece?
Generally, 1500 bytes is the maximum size of IP packets.
True, but you missed a key point, in that if 1000 users all need to view his video the sender doesn't need to send it at 1000* 1 Mbps only at 1Mbps as with multicasting the reproduction of packets is done close to the reciever within the telco cloud somewhere...Most digital video formats allow the author to determine the "bandwidth" of the video stream. In other words, if the video's author encodes the video with an assumed 1 Mbps (one million bits per second) bandwidth, then any client who wishes to view it without dropping frames needs to be capable of downloading at least 1 Mbps.
Only applicable on Ethernet... Transmission technology's care about Time Windows, and typically mupltiplex streams into 64K segments, for easier extraction. The Majority of Internet traffic (IP traffic) runs over these types of networks, its just inside the cloud from your perceptive.
True, but you missed a key point, in that if 1000 users all need to view his video the sender doesn't need to send it at 1000* 1 Mbps only at 1Mbps as with multicasting the reproduction of packets is don't withing the telco cloud somewhere...
They are not undefined, nor are they unnecessary, they are actually widely used, and essential in understanding Streaming Video. The whole concept, is based around Multicasting, from cable TV to streaming IPTV content to your Xbox.
Streaming video has nothing to do with ethernet, nor is it broken into 1500 Bytes.. To say so is wrong...
Anyway sorry for over complicating, but if you ask an advanced question expect an advanced answer
Nope you are right I didnt define them the IETF did. Honestly I disagree with your stance on this. I hate been treated like an idiot, and would prefer to have correct information. But you are an admin and I am not so you win.You did not define them in your response, so they might as well be undefined. I wouldn't expect anyone to go hunting for references all over the web just to make sense of your response. In general, it isn't a good idea to use acronyms or terms without first being sure that your audience knows what they mean.
By default, yeap, but nothing to do with the question.Okay. I'll concede that. At the same time, any computer connected to the internet via an "end-user" link like Ethernet or 802.11 will receive 1500 byte packets.
Ok I will concede that, it isn't an advanced question, but to attempt to give the correct answer you will need to get advanced. Because the whole concept revolves around Multicasting at layer 3 (IP addressing). You need an understanding of this to understand how video content is distributed, IMHO you cannot explain streaming video without touching on Multicasting.He didn't ask an advanced question. He asked this: Is it sent in small pieces or does data constantly flow from the source to the viewer? If so, how large is each piece?
Unicast is better quality and easier to control quality, the drawback is that each unicast session sends a stream to a single user making viewing by multiple users very expensive.Why does Unicast still exist? I can't find it's advantage over Multicast.
This has nothing to do with the OP's question. MPLS is a multi-location business wide area network. Sure you can do video over MPLS but this would only apply to a miniscule portion of BUSINESS customers.Only applicable on Ethernet... Transmission technology's care about Time Windows, and typically mupltiplex streams into 64K segments, for easier extraction. The Majority of Internet traffic (IP traffic) runs over these types of networks, its just inside the cloud from your perceptive. MPLS over SDH is an example, The IP is there but encapsulated inside MPLS and in turn encapsualted inside SDH (SONET for Amercians)
Look Multicasts, are unicasts up until you get close to the requestor. Thats the beauty of Multicasting. Unicasts is the bedrock of IP technology so most data movement is done with Unicasting.Why does Unicast still exist? I can't find it's advantage over Multicast.
Could you provide a link to this please? Cisco Stream Video content from there website for training and the likes all the time, I doubt they are breaking the law.I'm referring to streaming video over the internet.
Better quality? Why? As I already stated Unicasting is multicasting up till nearer the requestor. Quality of service can still be implemented with multicasting (within an Autonomus System [AS])The Quality is just as good. In fact I have been implementing a IPM monitoring tool using Cisco 2800 Routers, and HPov to First Application Test Multicasting and there is no quality degregration.Unicast is better quality and easier to control quality, the drawback is that each unicast session sends a stream to a single user making viewing by multiple users very expensive.
What are you talking about?The reason you don't see multicasting on the internet is that almost no internet providers in the US allow it because of the perceived revenue loss.
Becuase you don't seem to know how multicasting owrks over the internet.Evo it would have been quicker if you just posted the link, why did I force you to post that?
A telephone company is a business, small telephone companies are my clients. You don"t seem to understand how the backbone architecture is meaningless here. You're confusing people by throwing out meaningless information. I have been selling multicasting over the internet for years. I worked with our guys at Bell Labs developing the service when the other company I worked at decided to do a beta for a large international client of mine.I know MPLS in depth, and no it isn't a business only technology.
What gave you that impression?Becuase you don't seem to know how multicasting owrks over the internet.
I was explaining that it depends what protocol you use as to how this is achieved. Each different Layer 2 protocol, Transmissions protocol has a different way of breaking up frames.Is it sent in small pieces or does data constantly flow from the source to the viewer? If so, how large is each piece?
It's a product. It's not magic. How do you think people do multicasting? They have to buy a service.You sell Multicast over the internet? Thats a new one, how does 1 sell that?
You are very confused. First, I said that it is a business product, businesses use it, the public would be their end users. The PUBLIC internet is owned by the backbone providers, they are BUSINESSES. A person sitting at home (end user) is not going to buy an MPLS network in order to send and view video. You are confusing the matter. You have your telco environment and you think it applies to everything, you're wrong. AT&T is a huge internet backbone provider and their backbone is ATM, my company's backbone is just native IP, I don't think any of the major IXC's in the US use MPLS for their backbone, we sell MPLS that we can provide *over* our IP backbone, but we don't use it for delivering internet to the public.You were asserting that MPLS is only used with Buisness networks, I am saying you are wrong. It is used on the PUBLIC internet. If you like I will give you an IP address, and you can ping it, the icmp scho reply you get will have traveled across MPLS. 3rd tere Teleco's use it
You have your telco environment and you think it applies to everything, you're wrong. AT&T is a huge internet backbone provider and their backbone is ATM, my company's backbone is just native IP
Shows how little you know. Multicasting is a protocal which is actually sold as a product to businesses by some of the larger ISP's. You send them the video stream and they do the rest, for a price. My new company is the only one that will take the unicast stream and multicast it for no additional charge. The problem (if you read the FAQ I posted) is that if the end user and all routers between the host server and the end user are not multicast enabled, the end user will not be able to view multicast. In the US, Multicasting is not widely used, Unicast is. It's a fight between the ISP's Verizon and AT&T refuse to enable it in their network. Verizon's VP of Technology claims it's not a viable technology, which isn't true. But he's slamming it because they don't have it, we do. "Elby said that Verizon has taken this approach because IP multicast technology is not ready to scale to the size needed to deliver broadcast services. Elby pointed out that Verizon's video-on-demand services are based on IP technology, because on-demand video can be delivered to a user via a single unicast stream. But multicast IP is a whole different story.Evo, I think you are confused.
Multicasting is a protocol, not a product. I would buy a connection to the World Wide Web from a teleco (the service), then I would implement Multicasting on my own, with my own equiptment.
It's both, it's a product which is sold, I know, I've sold it. Just because you aren't aware of that doesn't make it disappear. Just like MPLS, Frame Relay and ATM are all "products" that are sold.If however I deside to outsource my network to you, then I would expect you to provide multicasting for me, but it is not a product it is a function, or rather a protocol that is handled by routers.
Very, very limited in the US.We are talking about how Video is streamed: Multicasting.
Ah, you read my FAQ.Implementing Multicasting to obtain Publically routed Multicasts is actually very easy, You need a router that has the Memory to withstand BGP, then you need to get a Class D address and Vola You can multicast, I don't need to buy the 'multicasting product' from At&t for that, I just need the correct IP addressing, and the appropriate hardware, and the ability to advertise my routes tothe public, via BGP.
No it isn't Evo, Perhaps in the Sales department you attempt to package it as a product. But it isnt, as an Engineer I engineer these solutions, and I know how it works, and I know I don't need you to process streams for me, if I can get my hands on a class d public IP address, as I explained before, before I know for a fact most if not all Good ISP process Mcasts.Shows how little you know. Multicasting is a protocal which is actually sold as a product to businesses by some of the larger ISP's.
Nope, I didnt need to, I am a ccnp (With ccie written) Network Engineer I eat this stuff for breakfast...Ah, you read my FAQ.
And then maybe a handful of people can view the stream, if you're lucky, because every router in the internet between your server and the end user must be multicast enabled, and almost none are.
MPLS ATM can be sold as products, but multicast isn't a product, because multicasting is part of IP.. It is just a CLASS D ADDRESS. All you need to do is to enbale it globally on a router, and route class D prefixes via BGP if you want public streams, and any other multicasting protocol if you arent, like mospf.It's both, it's a product which is sold, I know, I've sold it. Just because you aren't aware of that doesn't make it disappear. Just like MPLS, Frame Relay and ATM are all "products" that are sold.
So the great firewall of the States is filtering out BGP Mcasts? This is just so wrong...Very, very limited in the US.
As for this link:Level 3
Level 3 currently provides multicast connectivity/transit and will run native pim sparse-mode, MSDP and mBGP to any customer on any Level 3 Internet interface.
Multicast connectivity is included part of the basic service offering for no extra charge.
There are no limitations imposed on the use of multicast.
Just request it from your sales representative or call
I tend to think this is the problem. The information is outdated.Note that the supplied information can be slightly out-dated, as the CastGate project is still evolving, and updates to the
See, this is a perfect example of you not knowing what you're talking about, this has nothing to do with them multicast enabling their IP backbone so that end users can view multicasts via the internet.Anttech said:Verizon won't carry other Triple Play ISP's TV content, but that isn't the same as Public Mcasts, are you aware of that? You do know the difference between the two don't you? I think that is where you are confused. It is very easy to filter that stuff out without breaking the Mcast public routing table.
See, this is a perfect example of you not knowing what you're talking about, this has nothing to do with them multicast enabling their IP backbone so that end users can view multicasts via the internet.
You seem to be unable to understand the difference between multicasting over cable or Verizon's plan to offer it over fiber to a subscriber's premise (FiOS) and multicasting over the public internet. They are not the same.
Level 3 is a business to business only company in the US, they do not sell to non-business customers.Did you even look at the link I posted, regarding the level of Class D routing? Level 3 is the "main pipe" of the world...
This has nothing to do with the Telco environment. To do multicasting to non-dedicated business internet users, you need to be on one of the 2-3 ISP's that offer multicasting to consumers, since these ISP's mainly only sell to businesses, there are very few consumers on these companies. If someone wants to view your video and they are on an ISP that isn't multicast enabled (the vast majority) the instant your ISP hands off to their ISP the multicast stops. You do understand hot potato routing?Routing Multicasts is transparent to Telco's its like routing Unicasts, as I explained before. It is the same thing, up till closer to the requestor, or rather up till what we call a Rendevous point for the Mcast group.
Uhm, no. See you don't understand.I know what the confusion is about here, you are talking about IPTV over dsl or whatever.
Youtube isn't Live. Its a recording that's the difference, and the reason why they wouldn't multicast.. You would never multicast that type of content!The OP is not a business, he is a consumer, as are the vast majority of anyone reading in this forum. Video on the internet is gaining popularity, but because of the multicast issue, popular sites like youtube actually use flash.
True, but there is live video with the flash media server, but I'm not knowledgeable about the limitations.Youtube isn't Live. Its a recording that's the difference, and the reason why they wouldn't multicast..