TORONTO — With the popularity of Netflix continuing to grow — at last count, the streaming service boasts more than 104 million users in 190 countries (not to mention all the unpaid ones who are sharing passwords with a paid user), Internet service providers looking to improve their customers’ streaming experience can do so with a little help from Netflix itself.
As part of its Open Connect initiative, Netflix has worked for several years expanding its global ISP partnership network to bring its inventory of TV and movie content closer to customer markets by having ISPs either embed Netflix Open Connect Appliances (OCAs) in their networks, or connect via settlement-free interconnection (SFI) peering to Netflix OCAs in its global data centres. As it stands now, however, current Canadian government regulatory policy has prevented Netflix from establishing such peering locations in Canada.
However, for Canadian ISPs who would like to host OCAs within their own networks, Netflix will provide the necessary server hardware free of charge to ISPs – but only those which can support 5 Gbps of peak traffic. By placing OCAs in their networks, ISPs are able to localize Netflix traffic, bringing popular content closer to users and reducing traffic on transport networks – which makes the viewing experience much quicker and with far less signal degradation.
At the 2017 Canadian ISP Summit on Monday afternoon, Peter Cohen, partner engagement manager for Netflix, visiting from Washington, D.C., explained how Netflix’s infrastructure works and how ISPs can benefit from the Open Connect program. First of all, the Netflix.com website is hosted on Amazon Web Services (AWS), Cohen explained, not on Netflix’s own AS2906 (autonomous system) network. However, Netflix does operate its own infrastructure, which consists of a control plane and a data plane, Cohen said. The control plane handles the user request and initiates the playback process, taking into account a number of factors, such as user location, device type, language and the network connection being used, before streaming begins.
Before the requested TV show or movie is served up to the user, the Netflix control plane will determine if the user is on an Xbox, Smart TV or set-top box, or if the connection is over a cellular network or Wi-Fi, for example, Cohen said.
“Before anybody presses ‘play’, we have to determine a number of things,” Cohen said. “We’re able to have different bit rates for constrained networks. We get a lot of inquiries from people who are on ships using satellite, they’re on oil rigs using satellite, they’re in rural areas using WISP (wireless Internet service provider) connections…There are a number of factors that are all taken into consideration.”
The control plane also determines the best location where the TV or movie content should be streamed from, Cohen explained. In the case of an ISP that has embedded Netflix OCAs in its network, the control plane will most likely choose the ISP’s own Netflix box as the best server location, assuming the requested title is available in the ISP’s local content library, Cohen said.
Then the data plane handles the actual streaming of the TV show or movie, Cohen explained. The OCAs consist of two flavours of servers: high-capacity storage boxes, in a 2RU (2 rack unit) format, that can hold 220 terabytes of content and deliver 18Gbps throughput on 2 x 10Gbps ports; and faster-speed flash boxes, in a 1U format, that can hold 14 terabytes of data and deliver 36Gbps on 4 x 10Gbps ports. According to Cohen, some of the flash appliances deployed in Netflix data centres now support 100Gbps throughput speeds.
The higher-capacity storage boxes hold the bulk of Netflix’s content library for a given geographic location, with the flash boxes used to store and deliver quickly the most popular content to users, Cohen explained. Multiple redundant copies of Netflix’s content libraries are located at each OCA site to ensure users are able to access the content they want even at the busiest times on the streaming service, Cohen said. Nightly updates keep the flash appliances current with the most popular TV shows and movies as user viewing preferences change. These updates, or “fill” traffic, are done during off-peak hours to minimize disruption, Cohen said.
“There are a number of different versions of each episode (of a TV series), for different devices and different bit rates, so you may have something like 50 different copies of a single episode of a show.” – Peter Cohen, Netflix
Cohen went on to explain that although it’s a given to have a popular show such as Stranger Things available on the flash appliances for quick delivery to users, a lot of back-end work is done to optimize what content is actually stored on those flash boxes.
“There are a number of different versions of each episode (of a TV series), for different devices and different bit rates, so you may have something like 50 different copies of a single episode of a show. Of course, we’re not going to put the less popular versions of those episodes, even of a popular show, on that box. They’re going to sit somewhere else for that one time that somebody calls up a lower bit rate or some obscure bit rate that we may have to have,” Cohen said.
In the case of an ISP that is hosting its own Netflix OCA, if for some reason the TV show requested by the user doesn’t buffer soon enough from the ISP’s server or simply stops mid-stream, the content will continue streaming from another location, Cohen said.
“So, you’re watching it locally in Toronto from a server on your ISP in Toronto, and it dies. You may never notice that it was then delivered from another box in the States or somewhere else, that same title, so that your viewing isn’t interrupted,” he said.
Cohen pointed out that Netflix streams 125 million hours of TV and movies a day, “which is just an insane amount of Internet traffic,” he said. To help users determine what kind of connectivity speed they would experience watching a given title, Netflix has a website called Fast.com that lets Netflix users gauge the connectivity level they would get from the server delivering the content they want to see, Cohen said.
For more information about Netflix’s Open Connect program and ISP partnership options, click here.
