HOW PUBLIC INTERNET IS FINALLY READY FOR HD VIDEO BACKHAUL

Transcription

1 White Paper HOW PUBLIC INTERNET IS FINALLY READY FOR HD VIDEO BACKHAUL EXPLORING THE CHALLENGES AND OPPORTUNITIES OF DELIVERING MORE CONTENT AT LESS COST Today s broadcasters are faced with an ever- present reality: a desire for live, low latency HD video content. Traditional methods like satellite and fiber network distribution meet these requirements, but come at a cost that limits the amount of content that a broadcaster can afford to deliver. As audiences crave ever- more content, broadcasters are searching for other opportunities to get it to them at a lower cost. This paper explores the technologies that facilitate the distribution of secure, live, HD video over low- cost Internet connections, helping broadcasters fill their audience s insatiable need for more content.

2 INTRODUCTION There is no doubt that video consumption is increasing. Both consumer and enterprise audiences are turning to video to stay abreast of information and events that are important to them. This poses a challenge to broadcasters who are trying to meet that demand by delivering increasing amounts of content. In the past, broadcasters have relied on satellite provisioning or fiber networks to deliver high- quality, low latency video content. While these connections are reliable and secure, they are expensive. Due to the nature of the satellite connections, it can take time to provision the links, and broadcasters must negotiate bandwidth consumption, which limits the amount of content or the quality of the content that is being distributed. MPLS networks require installation and maintenance over time. These solutions lack the flexibility broadcasters need to deliver competitive, relevant and timely content within a reasonable cost structure. To address the challenges of satellite and MPLS video delivery and meet increasing demand for live video transport, a number of new technology innovations are now available to broadcasters providing alternative methods of video delivery. As broadcasters evaluate these solutions, they should consider technologies that allow them to: Quickly provision remote feeds for news and events contribution Eliminate the cost of satellite and dedicated networks for remote feeds Monitor remote operations and productions Connect facilities with live video to increase workflow efficiencies CHOOSING THE PUBLIC INTERNET AS A DISRUPTIVE ALTERNATIVE In recent years, broadcasters have looked to the Internet as a potential means to quickly provision multiple remote feeds for lives news and events contribution. Although the Internet has proven to be moderately successful at accommodating file transfer and high quality media streaming, it is still wrought with challenges when transporting live, HD video. THE INTERNET AND ITS CHALLENGES From the moment a video stream leaves a private network (LAN), it passes through many different networks (WAN) whose objectives are to maximize their resources. 2 P age

3 Packet loss, jitter, latency and the fluctuation of bandwidth are challenges that need to be overcome when attempting to transport live video over the Internet. Packet loss is a particularly important problem when transporting compressed video, as its effect to the end product can be extreme. When video is faced with network congestion, the network has no other option than to drop packets as the video passes through. If only one packet of information disappears, it can affect a single block of video in a frame, the entire frame of video or the entire sequence of video. Network speeds and congestion are unpredictable; viewers can go from fluid real- time video to a frozen image in less than a second. PACKET LOSS YOU SHOULD PLAN FOR: <0.001% over an MPLS network <0.1% in a building <0.5% across a campus ~1% over the Internet (stable network) ~5% over the Internet (unpredictable network) TRANSPORTING LOW LATENCY LIVE VIDEO OVER THE INTERNET Although transporting high quality, live video over the Internet is challenging, using today s protocols and technologies, it is possible. Focusing on some of the most widely used protocols and technologies, we ll explore the advantages and disadvantages of each technology as it relates to transporting low latency, secure, HD video over the Internet. FRAGMENTED STREAMING Fragmented streaming is one of the most commonly used technologies to transport video over the Internet, slicing video content into 1-10 second files. When the video reaches its destination, the video files play sequentially with no visible break. Although this method is effective, it takes time. The stream needs to be encoded, captured into a segmented file, sent over the network and finally collected into a buffer before reaching its end point. One 3- second file segment can compound into 30 seconds or more of overall delay before reaching its final destination. 3 P age

4 FORWARD ERROR CORRECTION (FEC) FEC rebuilds missing packets by reverse calculating redundant information sent with the base data (similar to RAID hard drive technology). When the information is about to leave the source (encoder), redundant information is calculated and added to the stream to allow for the reverse recovery calculation to be performed should a packet go missing. FEC does incur a bandwidth overhead related to how resilient the stream needs to be (typically less than 20%). FEC will introduce additional delay - the time needed to build the redundant information and to confirm all expected data (packets) have been received or rebuilt (typically milliseconds for a good implementation). FEC is known for its performance with more predictable networks that have less packet loss, a secure campus network or a satellite connection for example, however, when faced with an unpredictable network and unforeseen packet loss that FEC cannot account for, such as the public Internet, the stream can grind to halt. PACKET RETRANSMISSION Packet Retransmission is the basis of TCP/IP, a protocol used in almost all Internet transmission of information (files, web pages, etc.). TCP/IP assigns a number to every packet sent. The sender holds onto a copy of the packet until the receiver acknowledges that it has received the packet. If no acknowledgement is received within a certain time, the sender resends the packet. Packet retransmit requires a level of patience. Send, receive, acknowledge, send back, wait, send back, resend, re- acknowledge. Although this solution is effective, low latency implementation for live video has been illusive. 4 P age

5 THE FIREWALL Your firewall is there to protect your internal network from the outside world, but not to prevent you from exploring the outside world. The basic principle is simple; if you are inside the firewall and request something from the outside, your firewall allows the outside to send it to you. Internet video streaming is no exception; the viewer is in charge of requesting a stream from a streaming server once the request has been made from behind the firewall the server can then send the stream. With circuit- style broadcast links the relationships are slightly more complicated. The requestor could be within the firewall at either endpoint, or in the neutral ground of the cloud. Control over the request flow is critical to working with the natural dynamics of a firewall rather than fighting with them at every location. Although today s widely used protocols and technologies facilitate the transport of live video over readily available, low- cost Internet connections, they lack the ability to meet broadcasters requirements for live backhaul contribution. INTRODUCING SRT Haivision, an enterprise video technology company with decades of experience in transporting video over any network, has developed a revolutionary technology supporting the transport of secure, live, HD video over readily available Internet connections. Haivision s SRT (Secure Reliable Transport) optimizes streaming performance across unpredictable networks like the Internet, offering significant operational flexibility and cost savings over, or compared to, satellite and custom network infrastructures. SRT is a combination of best in class protocols and proprietary technologies, allowing broadcasters to quickly provision remote feeds over low cost networks for live news and events contribution. HOW SRT WORKS SRT is applied to contribution and distribution endpoints as part of a video stream workflow. After encoding, SRT applies AES encryption and provides error recovery. Prior to decoding, SRT decrypts the stream and recovers from packet loss typical of Internet connections, facilitating the transport of low latency video. SRT also detects the real- time network conditions between encode and decode endpoints, allowing broadcasters to determine how to configure the encoders so that the available bandwidth is not oversubscribed, avoiding network congestion. SRT as a protocol works with very little additional end- to- end delay. 5 P age

6 FIREWALL TRAVERSAL MADE EASY WITH SRT Provisioning multiple streams across unknown networks can be a challenge. This is exemplified when running an event from a hotel or conference center and attempting to traverse its unknown Firewall. Firewall traversal depends on a specific handshaking sequence between the source and destination. Firewalls are typically friendly to internal requests, so it is important that whatever is provisioned within the unknown network can be configured as a caller. With SRT, devices can be configured as callers to initiate requests, listeners to respond to requests, or placed in rendezvous mode, enabling multiple callers to accommodate the worst- case scenarios of multiple unknown networks. CONCLUSION Whether aggregating SRT streams over the Internet from multiple remote production venues with the Haivision Media Gateway, or delivering low latency, secure, HD video streams with Haivision s award winning Makito X Encoder and Decoder, Haivision solutions have allowed broadcasters to re- imagine their live backhaul infrastructures. Gone are the days when cost- effective meant sacrificing quality. The evolution of digital distribution and its supporting technologies has paved the way for Haivision to develop a true alternative to traditional methods of live video distribution. Haivision s SRT provides broadcasters with a high performing, scalable and cost effective solution for live backhaul over any network. LET US HELP YOU WORK BETTER WITH VIDEO Haivision s goal is to help people and organizations work better with video making it easier for their video content to reach the right audience within a network or over the Internet. Recognized as one of the most influential companies in video by Streaming Media, Haivision delivers solutions for streaming, encoding, recording, managing, and distributing secure video and interactive media. When you re ready to talk solutions, give Haivision a call at or us at [email protected] and let us help you find how Haivision solutions can help. We know that no two companies are the same, so we ve built our flexible services to help you deploy the tools that best help you solve your video management and publishing challenges. 6 P age