The AV industry has an alphabet soup of acronyms. In fact, “AV” is the shorter version of audiovisual. It’s kind of our thing. HDMI, HDCP, DVI, VGA, SDI, and more. We love our letters. AV over IP is another example of that.
Simply put, AV over IP is the technology that lets you send audio, video, and control signals on a standard IT infrastructure. Nothing more. But, it’s how you get there where the hurdles come in. Which “flavor” of AV over IP is right for you and your organization? What’s the impact on the network? Will it look good? Is it always reliable? All great questions.
Sit back and let’s get into the world of AV over IP.
AV over IP Basics
Spend even a little time around Commercial AV today, and you’ll surely hear the phrase “AV over IP.” Short for Audio Visual over Internet Protocol, AV over IP means using a standard switched network, like your office’s local area network, or LAN, or even the Internet, to distribute audio, video, and control signals over standard switched networks. AV over IP promises significantly reduced cost, extended range, and superior remote management of your organization’s AV systems.
Key Concepts
In an AV/IP setup, an AV source, such as the HDMI output from a camera and mic, is fed into an encoder. The encoder connects to a standard IP network. A decoder connects to the destination at the receiving end, such as the display and speakers in a conference room. However, it could be a streaming or broadcast system or anything else you might integrate into your AV system.
When you’re designing or specifying a system, make sure to distinguish AV over IP from HDBaseT or other point-to-point AV transport systems. Architecturally, the two share many similar elements. HDBaseT has A/V Transmitters, A/V Receivers , and an A/V switch instead of Encoders, IP switches, and Decoders. Both use the same Ethernet cable and jacks as IP computer networks, but HDBaseT will not run over an IP switch.
Using your organization’s existing IP network rather than a dedicated AV network provides much of the advantage of AV over IP. You don’t have to pull an additional set of cables. Ethernet’s economies of scale make adding additional ports via IP switches fairly inexpensive compared to purchasing additional HDBaseT A/V switches. AV/IP can achieve significant cost savings; some estimates are as high as 40%!
Transport Protocols
AV/IP can use standards-based or proprietary packetization for transmission over IP networks and switches. Packetization is the core of IP, essentially breaking down data into small ‘packets’ of information that contain routing and sequence information so the data is sent to the correct location or locations and reassembled in the proper order.
Like any other IP network-based solutions, AV over IP systems employs transport layer protocols to define how data packets are formatted, transmitted, and received.
The transport protocol, such as TCP/IP, provides end-to-end services for applications such as reliability or assurance, which verifies the data was received; connection-oriented communication, which verifies that a session, or connection, has been established before data is transferred, flow control, which ensures data is sent no faster than it can be received, and more. TCP/IP, UDP/IP, and RTP/RTSP protocols are commonly used in AV/IP.
Terminology
The world of AV over IP has their own language. In this section we’re going to cover those that are most critical when designing and specifying a system.
Chroma Subsampling
Chroma, or chroma subsampling, in the AVoIP world refers to way a codec encodes the images and video. It is rendered with three numbers. 4:4:4 would be an example. The first number is the horizontal sampling reference, second is number of chrominance, and the final is number of changes in chroma samples. The higher each number the more complex and more bandwidth required. Lower numbers will directly correlate with lower bandwidth.
Resolution
Resolution is the size of the image being sent. This is written in terms like HD, 4K, or 1920X1080. These are the number of pixels that exist within the video or graphic image. Like chroma, the higher the number the more bandwidth required.
Refresh rate
Refresh rate is how many time per second the image is drawn on a screen. Illustrated in terms like 24, 60, or 120Hz. Much like chroma and resolution, the higher the number the more bandwidth required.
Higher numbers are typically associated with higher quality images. Though that is not always the case. It’s not a one-to-one correlation. Even though the bandwidth is higher, always try to test out encoders and decoders in your system before specifying and deploying network-wide.
CODECS
AV/IP equipment includes various codecs for handling video and audio. Standard video codecs include H.264, aka MPEG-4 AVC (Advanced Video Coding), and High-Efficiency Video Coding (HEVC), H.265, which offers better quality at lower bitrates than H.264. SDVoE, Software Defined Video over Ethernet, is an open standard employed by a host of manufacturers that takes advantage of 10 GB networks to offer multiple 4K HDR video streams.
Many AV manufacturers use proprietary codecs in order to deliver high quality video at low latency. They are not compatible with other standards. Open standards-based AV over IP solutions can, but only sometimes, interoperate with products from other vendors. The real-world impact is that, in most cases, you need to purchase encoders and decoders from the same manufacturer even if two different brands both specify that they use the ‘same’ codec.
In a majority of solutions, audio can be transmitted independently from video signals. Popular audio codecs include AES67, the Audio Engineering Society standard for audio over IP, and Dante, a widely adopted proprietary low-latency, high-quality audio spec.
The SMPTE ST 2110 standard was designed for broadcast environments that employ the RTP (Real-time Protocol) transport protocol. It separates video, audio, and other data into separate IP streams. It promises to become more common in commercial AV as corporate video production becomes more sophisticated.
You should always research if a product is ‘wide open’ and capable of working with encoders or decoders from different vendors. You’ll have a much smoother experience integrating your project!
AV over IP Network Considerations
There are countless reasons why organizations decide to migrate from an existing hardwired AV system to a more modern AV over IP solution—from increasing cost-efficiency to unlocking simplified collaboration and content sharing across an enterprise. Here, we’re zooming in on some of the most important networking considerations that occur when replacing traditional AV configurations with IP-based network infrastructures.
But first, what’s the key difference between distributing and managing audiovisual content through IP networks versus a hardwired integration?
In a traditional system setup, AV equipment like conference room displays, speakers, and microphones are connected via physical cables with a practical limit of a few feet, often requiring connected devices to be located relatively close in proximity. Upon that, hardwired systems also use what’s called circuit-based switching to distribute AV signals, all of it routed and controlled via a matrix switcher with a fixed input-output capacity.
AV over IP, on the other hand, uses your organization’s IP network, or a stand-alone private network, to transmit high-quality audio and video seamlessly—just like connecting to the Internet on your computer or laptop. Instead of relying on dedicated cables and limited hardware, audiovisual devices are connected to the network using Ethernet or Wi-Fi through an IP switch.
Data, Bandwidth & Latency
Here’s where we’ll find that data transmission over the network infrastructure starts to illustrate the primary differentiating factor for AV over IP systems.
Once all audio, video, and control signals in an AV over IP setup are integrated into the IP-based network, they are formatted into the Internet Protocol (IP) data standard and transformed into digital packets.
Now, if we imagine these data packets traveling through a digital highway on the network instead of traditional routes, then bandwidth is like the capacity to travel smoothly.
In an AV over IP system, having enough bandwidth is crucial for preserving content that looks and sounds great without any interruptions or delays.
To ensure an efficiently functioning ecosystem with a variety of sources and endpoints, optimizing bandwidth typically involves implementing a few strategies, such as video and audio compression to retain AV fidelity, adjusting resolution and frame rates for effective content delivery, and prioritizing critical data streams through network settings.
Many of these same strategies contribute to reducing and keeping latency at a minimum. Latency refers to the delay between the transmission of AV data from a source to its display on an output device. You can think of this as AV “lag,” leading to synchronization issues and a much less seamless user experience. Another way to reduce latency includes configuring IP switches and all devices in the network infrastructure to be optimized for fast processing capabilities, improving streaming quality and updating firmware/software.
Ensuring Network Security
To round out our overview on networking considerations for AV over IP system integrations, let’s walk through a misconception. Transitioning from hardwired to IP-based is sometimes thought to bring more network security risks. However, fear not; with increased flexibility and modern deployment options, proven methods can protect sensitive data and prevent unauthorized access.
Important security best practices include using encryption protocols to ensure secure data transmission, implementing access control mechanisms such as authentication with usernames/passwords or biometrics, deploying firewalls and intrusion detection systems for network protection, and conducting routine security audits, firmware updates, and patches to uphold system integrity and adhere to IT security standards.
It’s possible to significantly increase the chances of maximizing the practical value in your AV over IP deployment by taking the time to understand and incorporate a few fundamental networking considerations, as well as simply adopting new capabilities with the right technologies.
AV over IP Standards
In our introduction to AV over IP, we discussed some of the standards that make it possible. In this lesson, we will discuss them more thoroughly and add some standards. Remember, some AV over IP solutions – even ones based on “open” standards – won’t interoperate with products from other vendors. It’s critical to verify that a product you’re considering will interoperate with solutions from all the vendors you’re working with!
AVoIP can use standards-based or proprietary packetization for transmission over IP networks and switches. Packetization is the core of IP, essentially breaking down data into small ‘packets’ of information that contain routing and sequence information so the data is sent to the correct location or locations, and reassembled in the proper order.
Like any other IP network-based solutions, AV over IP systems employs transport layer protocols to define how data packets are formatted, transmitted, and received.
The transport protocol, such as TCP/IP, provides end-to-end services for applications such as reliability or assurance, which verifies the data was received; connection-oriented communication, which verifies that a session, or connection, has been established before data is transferred, flow control, which ensures data is sent no faster than it can be received, and more. TCP/IP, UDP/IP, and RTP/RTSP protocols are commonly used in AV/IP.
IP or Internet Protocol – All AV over IP solutions employ the Internet Protocol, the set of rules that control how packets of data are addressed and routed across your local network and, in fact, the Internet itself.
TP or Transport Protocol – Transport protocols control how data is sent and received across the network. The Transmission Control Protocol (TCP) isn’t the fastest, but it ensures all packets arrive in order and confirms that they are received. (Missing packets will be recent.) User Datagram Protocol, UDP/IP is faster than TCP, but it does not ensure all packets are delivered in the correct order.
RTP/RTSP – The Real-time Transport Protocol, RTP, and Real-time Streaming Protocol, RTSP, are application-level protocols core to AV over IP and other ‘one-to-many’ or multicast video streaming. RTSP starts and ends the stream, RTP transmits the video data, while RTCP monitors the quality of service and other stats. RTP is usually run over UDP/IP, and its prime goal is to prevent the video from impacting other network services, i.e., minimizing network congestion by adjusting the data rate.
SDVoE – Software Defined Video over Ethernet, aims to “accelerate the replacement of point-to-point connectivity and the matrix switch with Ethernet-based AV distribution.” The SDVoE Alliance includes designers, integrators, and many manufacturers. Its primary advantages include flexibility, a ‘full stack’ approach to designing the protocol, and support for multiple 4K HDR video streams on 10 GB networks.
Dante AV – A combination of software, hardware, and network protocols, Audiante’s Dante delivers uncompressed multi-channel, low-latency digital audio and up to 4K 60 4:4:4 video over a standard gigabit IP network. It promises interoperability between more than 4000 products from over 600 manufacturers.
SMPTE ST 2110 – The SMPTE ST 2110 standard was designed for broadcast environments that employ the RTP (Real-time Protocol) transport protocol. It separates video, audio, and other data into separate IP streams. It promises to become more common in commercial AV as corporate video production becomes more sophisticated.
NMOS -The Networked Media Open Specifications is a “family of open, free-of-charge specifications that enable interoperability between media devices on an IP infrastructure.” NMOS offers a manufacturer-neutral way to connect SMPTE ST 2110 senders and receivers. It is open, free of charge, and provides many control, configuration, and security features not included in ST 2110.
IPMX – Internet Protocol Media Experience is an “emerging” open standard for AV over IP that promises to bring interoperability for Pro AV clients, much like NMOS offers for broadcast.
AV over IP Products
Most organizations have already crossed the bridge into business operations that rely on the day-to-day communication of digital content and real-time video collaboration. A well-designed AV over IP solution can facilitate seamless and high-performance audiovisual experiences with ultimate control over all of this content, improving engagement with and the inherent value of daily communications and digital sharing.
A clear understanding of the key technological elements and network requirements is pivotal to a successful AV over IP deployment. Apart from the high-resolution displays, audio systems, conferencing cameras, management software, and other common peripherals as part of the integrated solution, let’s examine what’s exactly at play with an IP-based signal distribution infrastructure.
Encoders & Decoders
These devices are crucial for converting audiovisual signals into IP packets for transmission over the network, and then decoding them back into usable signals. Encoders capture content from sources such as cameras, computers, and media players, converting them into digital streams. Decoders receive these streams and convert them back for display on screens or other output devices.
Plus, a key advantage of AV over IP is its scalability—additional encoders, decoders, and endpoints can be easily added to accommodate growing business needs without significant infrastructure changes.
IP Network Switches
High-performance network switches with support for Gigabit Ethernet or higher, in addition to Quality of Service (QoS) capabilities vital for handling the high-bandwidth requirements of most AV environments, serve as the control hubs for the system. They facilitate the routing and distribution, or switching, of audiovisual data across the network, enabling streamlined control of what you see, when, where, and how.
Network Infrastructure Components
Supporting the data-intensive nature of AV over IP systems hinges on a robust, capable and scalable network infrastructure. This means selecting the appropriate high-speed Ethernet cables, Cat6a or fiber optic cables for long-distance transmission, network switches with fast processing capabilities, and network security measures to protect data integrity.
Private versus Public Network
When deciding on an AV over IP system, one of the major considerations is whether to have an isolated, private, network or use the existing company infrastructure. Oftentimes this public network is referred to as the “production” LAN.
A private network allows for the full use of the network’s bandwidth. There is no sharing of resources for email, internet browsing, or other applications that use network resources. Setting up AVoIP on a production LAN means the system will compete with bandwidth available for sending AV signals. There are benefits for doing either.
Using a private network means you can use all the bandwidth and not share with any other applications. The network is isolated from other traffic and network security concerns. Leveraging the existing production LAN means no need to create a completely separate network. A private network will need a connection to the public LAN for monitoring and management.
Control Systems
AV over IP systems come to life with centralized control systems to manage various AV devices in-person or remotely. These systems typically integrate with user-friendly interfaces, including touch panels, mobile apps, and software-based platforms, providing intuitive control and monitoring of the system. All in all, they empower users to switch between sources, adjust volume, control displays, and automate workflows—enhancing the overall user experience.
AV over IP Solution
AV over IP gives organizations the ability to distribute AV systems all over their campuses and world. Using this technology, you can bring information and collaboration anywhere there is a network signal. That does not mean designing and specifying one is without it’s challenges.
Keep in mind what it is you’re trying to do. What problem are you trying to solve. If it’s displaying a simple laptop locally then maybe an AVoIP solution isn’t right for you. However, should you ever need to get that local signal anywhere else on your campus or network, it’s the perfect answer to that problem.
Bandwidth, image resolution, and chroma sampling are all considerations when designing a system. The higher the resolution and chroma the more bandwidth will be required. This will also lead into what type of network to deploy. Using either a new, private, network or leveraging the production LAN will be part of your design consideration.
AV over IP can be the answer to a multitude of problems. Start with what you’re trying to solve and work back from there. If AV over IP is the direction you decide to head, we’ve hopefully given you the tools to make an educated decision.
