AV Over IP
UNDER REVIEW
Introduction
This chapter covers the primary components, common features, and best practices for planning, designing, and deploying AV over IP.
AV over IP is a method of transmitting (encoding), receiving (decoding) AV signals and routing the content as a data stream via IP network connections. This routing method functions much like a standard AV matrix switcher, with improved flexibility and scalability afforded by enterprise network switching and routing.
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Scope of this Chapter

This chapter focuses on the technology and key relationships required to deliver low latency transmission of AV data over IP networks for commercial AV integrated technology. Transmitted AV data includes the following data types:
  • Video
  • Audio
  • Control
  • USB data:
    • Keyboard & mouse data
    • Camera & microphone data
    • File transfer data
Wireless presentation, and IPTV are outside the scope of this document.

Glossary of Terms

Term
Definition
Air-gapped
A network security measure employed to ensure that a network switch is physically isolated from all other network switches
Application Programming Interface (API)
A sets of functions and protocols through which software may interact with an application, AV system component, third-party software, or sub-system.
AV System
A multimedia presentation system for video and audio presentations
AV
Audiovisual (AV) encompasses the integrated devices for managing the routing, processing, and presentation of video and audio content. It may also include associated AV network data streams, user control interfaces, automation processes and integrations with other systems, to name a few.
Bitrate;
Data rate
Relating to digital devices and the transmission of data streams, bitrate is the number of data bits that are transferred per second
Broadcast
A network message transmitted to all connected devices on the same subnet as the sender device
Codec
A codec within the contet of AV, is a physical electronic circuit or a software method of compressing and decompressing video data.The word “Codec” is sometimes used to refer to a hardware or software encoder/decoder system; the word is a portmento of Code-Decode.
DHCP
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on IP networks whereby a DHCP server dynamically assigns and manages IP addresses and other network configuration parameters to each device on a network so they can communicate with other IP networks.
Encoder/Decoder
Hardware or software designed to encode and/or decode a digital data stream. An encoder is used to encode a video signal so it may be streamed or saved as a video file. A decoder is used to decode a video file or incoming data stream so that it may be viewed or stored on a device
HDCP
High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection developed by Intel Corporation[1] to prevent copying of digital audio & video content as it travels across connections. Types of connections include DisplayPort (DP), Digital Visual Interface (DVI), and High-Definition Multimedia Interface (HDMI)
HID
Human Interface Device is a peripheral that connects to a computer to allow a user to interact and provide input. Examples include a keyboard, mouse, touchscreen etc.
ICT Architecture
Information and communications technology architecture encompasses the computers,servers, security, phone systems, and network switching and routing for an organisation’s network
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a professional association, formed in 1963 from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers, headquartered in New York City. The organisation is responsible for the creation of many international standards used in AV and many other fields.
IGMP
Internet Group Management Protocol is a communications protocol used by hosts and adjacent routers on IPv4 networks to establish multicast group memberships. IGMP is an integral part of IP multicast.
IGMP Snooping
The process of listening to Internet Group Management Protocol (IGMP) network traffic to control delivery of IP multicasts. Network switches with IGMP snooping listen in on the IGMP conversation between hosts and routers and maintain a map of which links need which IP multicast transmission. Multicasts may be filtered from the links which do not need them, conserving bandwidth on those links.
IGMP Snooping Querier
An IGMP Snooping Querier manages the messaging and updating of information related to multicast groups within a VLAN. Configuration of an IGMP querier is required to manage multicast traffic when no when no multicast router is present on the VLAN.
IP Address
An Internet Protocol (IP) Address is used for network communication between computer devices. The IP address allows a device to be identified on the network
IR
Infrared. In AV systems, IR is typically used for one-way control and automation of third-party controllable devices
LAN
Local Area Network (LAN) is a network of interconnected computers within a building or department
Matrix Switcher
Video routing AV equipment with the capability to route any input to any output, or route any input to multiple outputs
Multicast
Network group communication messaging where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution
Rendevous Point (RP)
A Rendevous Point is a router within a multicast-enabled network that receives and directs AV traffic and signalling messages between encoders and decoders. It can be configured within a router, or within some Layer 3-enabled switch models.
Picture-in-Picture (PIP);
A combined video image composed of two or more video sources. Combined images may be side by side taking up half the viewable area, or one image may take up the entire viewable area with the other displayed on an inset window positioned in the corner
QoS;
Traffic Shaping
Quality of Service is a method of prioritising specific, time-sensitive network data traffic to ensure it reaches its destination with minimal delay
RS232;
RS422;
RS485
A telecommunications standard for serial communication and data transmission. In AV systems, typically used for point-to-point two-way control and automation of third-party controllable devices
TCP/IP
A suite of communications protocols to connect computers on the internet and is the standard for transmitting data over networks.
UDP/IP
The User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, sometimes known as datagrams, to other hosts on an Internet Protocol (IP) network without requiring other communications to set up special transmission channels or data paths.
Unicast
A one-to-one transmission from one point in the network to another point; that is, one sender and one receiver.
VLAN / Subnet
A Virtual Local Area Network (VLAN) is a logical partition of a physical LAN allowing multiple devices to be physically connected to the same or different network switches and still be part of the same network, communicating with each other using MAC addresses to send and receive Ethernet frames between devices. VLANs are a Layer-2 concept, operating at the Data-Link layer.
A Subnet also provides a logical partition of a physical/virtual LAN, using IP addresses to send and receive Packets with each other, operating at the Layer-3 Network layer. Packets may be sent to other devices on the same subnet, or to other subnets through a router or gateway.
Subnets and VLANs are often deployed on a 1:1 basis for simplicity, but it is entirely possible to have mutliple IP subnets within a single VLAN.
For further informattion on the TCP/IP model, see *INSERT REFERENCE*
Wi-Fi
Wi-Fi is a family of radio technologies that is commonly used for the wireless local area networking (WLAN) of devices which is based around the IEEE 802.11 family of standards.
WLAN
A wireless LAN (WLAN) is a wireless network that links two or more devices using wireless communication to form a local area network (LAN) within a defined area such as a home, school, computer laboratory, campus, office building etc.
Zero-configuration networking (zeroconf)
A set of technologies that automatically creates a usable network based on the Internet Protocol suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manual operator intervention or special configuration servers.

Stakeholders

Below is a list of stakeholders commonly involved in the planning, deployment, and maintenance of an AV over IP solution:
    • AV and ICT Managers (design of integrated technology)
    • End Users (functionality, features, and user experience)
    • Facilities Management (passive network, cabling, cable paths & patching infrastructure)

Key Relationships for a Successful Implementation

Video encoding and decoding technology, as well as the underlying ICT enterprise network, are vital elements of successfully delivering an AV over IP solution. Equally crucial to selecting the correct hardware for the job is ensuring that key relationships are fostered between audiovisual and institutional network design & operational teams. Bringing these key stakeholders in with clear functional and technical requirements of an AV over IP solution, supported by vendor-specific whitepapers can go a long way in fostering healthy, respectful and successful relationships and deployments that are a joint effort between colleagues and teams.

Define the Requirements

Requirements Gathering

AV Over IP is suitable for consideration anywhere video signals need to get from a presentation source to a display device or system output. AV Over IP can be used to many varying degrees, and each have their place and suitability, depending on your institution technology requirements in the short and long-term.
Whether it’s getting a signal from A to B or completely replacing your existing AV transport approach, AV over IP can often be a cost effective solution that allows adherence and alignment with the standards already employed by the network and ICT teams.
Below is a list of common scenarios where the use of AV over IP may be applicable over traditional video transport approaches:
  • AV signal routing and distribution solution must be scalable for future expansion, at a room, building or campus level
  • Encoding every presentation source input and decoding content at all display devices and system outputs, allowing a ‘virtual’ AV matrix, completely replacing traditional AV transport methods
  • Augmenting traditional video matrix/switching technologies to expand system functionality with other examples found in this list
  • Content can be duplicated from a single presentation source to any number of displays or system outputs
  • Route content to/from AV systems across multiple rooms, buildings or campuses
  • Refurbishing spaces with existing network cabling and difficult or cost prohibitive building works requirements for direct point-to-point cabling solution.
  • Enhance remote monitoring, support and management workflow capabilities by employing network-connected transport solutions with signal health feedback.
  • AV solutions are required to comply with enterprise network standards and separate AV cabling is not allowed or preferred to be avoided
  • Opportunities to reduce hardware footprint in rack space and cost in traditional, large video matrix deployments
  • Content from multiple presentation sources may be presented simultaneously to a single display (Picture-in-Picture) or for Video Wall image processing
  • Live-streaming to displays, or computer devices on campus via the local network
  • Computers may connect to USB devices via the network, including the read/write of USB storage devices via the network

Technical Requirements

The table below describes common technical requirements and the associated design responses when deploying AV over IP:
Technical Requirement
Design Response
Current network architecture not suitable for AV over IP The network may not be designed to transmit AV over IP data streams satisfactorily, or with the appropriate bandwidth for the desired application
  • Deploy a dedicated network switch with appropriate network features for the AV over IP system
  • Ensure cabling and patching infrastructure meets specifications for AV over IP solution
A point to point AV over IP solution is required
An AV Over IP solution may be leveraged to connect two endpoints together that are on disparate network segments, or physically distant locations.
  • Multicast addressing may not be required, depending on hardware selection
  • Unicast video traffic must be supported between encoder and decoder
  • Uplink bandwidth between source and receiver must still be considered
AV over IP network must be isolated from other subnets ICT security policy may request AV over IP network traffic not negatively impact other network traffic.
  • Deploy a dedicated, air-gapped network switch for the AV over IP system
  • IGMP not required
  • Multicast address not usednot
  • Unicast or broadcast messaging
AV over IP codecs connected to different subnets, but must be able to stream across subnets
ICT security policy may require different device types be placed on different subnets
  • Network traffic must be routed between subnets
  • IP address ranges or domain names must be specified for AV over IP codecs
Proprietary codecs must not be used Users or institutional standards may require the use of various software and/or hardware devices to encode or decode video streams
  • Avoid proprietary codecs
  • Encoders and decoders to support open standard codecs (e.g. H.264, H.265, or Motion JPEG 2000)
Low end-to-end latency
The input lag from presentation source to display must be as close to real-time as possible
  • Deploy lossless codec hardware/software with low latency as a primary specification
  • (maybe define some recommendations on latency thresholds ie. <40ms end to end etc?)
  • Codec must be “uncompressed” or “lossless”
  • Avoid H.264, H.265 codecs as compression/decompression typically induces too much latency for the use of HID devices
Video must be highest possible quality
Video quality must not be compressed by the codec
  • Deploy a network switch with 10G Ethernet or SFP+ interfaces
  • Codecs must be “uncompressed”
Video must be high quality and network is 1Gbps
Video quality is high priority, but the network bandwidth throughput is limited to 1Gbps
  • Deploy a network switch with 1G Ethernet interfaces
  • Codecs must be “lossless”

Network IP Video Bandwidth Considerations

The first three columns of this table (Chapter XXX) provide the uncompressed video bandwidth of a signal, depending on resolution, refresh rate and colour depth. This information is provided to aid in understanding the various compression schema that are employed by AV over IP solutions.

‘Lossless’ Video Compression (Up to 1Gbps)

Consider the following when planning the deployment of codecs rated as lossless:
  • ‘Lossless’ products are often proprietary and encoder/decoder combinations must be of the same manufacturer and product range
  • Encoders and decoders based on the Motion JPEG 2000 video protocol fit within this category, however have the potential added benefit of interoperability between vendors . At present, due to vendor implementation of the standard and compression settings employed, encoders and decoders based on MJPEG2000 are often required to match manufacturer and product range, also. Check with manufacturers for interoperability between vendors and perform your own testing
  • Low end-to-end latency, often equal to or less than 50ms, suitable for lip-sync applications
  • Compression schema employed should be visually undetectable, producing a high image and audio quality.
  • Switch backplane, network topology, including uplink bandwidth capacity and rendezvous point location must be considered and discussed with network design/operations teams, as these solutions can place a significant amount of bandwidth on the data network, depending on network typology and configuration.
  • Always refer to the vendor-specific white paper or design guide for a list of required protocols when considering the deployment of this option

‘Lossy’ Video Compression (Up to 25Mbps)

Consider the following when planning the deployment of codecs rated as lossy:
  • Lossy codecs typically use open standard codecs such as:
    • H.264
    • H.265
    • MJPEG2000 at high compression ratios
  • Highest end-to-end latency due to encoding process time + network transit time + decoding process time
  • Tolerance for image and audio quality degradation required. Testing for specific applications, using the required content source and test display is recommended
  • May be suitable for deployment on networks with low bandwidth

Key Components

An AV over IP system is composed of four key components:
    • Encoders convert presentation sources, ingested via traditional video ports formats into a data stream to be transmitted over an IP network..
    • Decoders receive this data stream and convert it back to a traditional format for use with a display device
    • Management is the software running on processing hardware to facilitate the control and management of AV over IP codecs deployed throughout a campus

Encoders & Decoders

Function

AV over IP encoders and decoders are hardware devices, software protocols or a combination of both, whose function is to encode/decode AV signals for transport as a digital data stream across a communications network using standard protocols. They offer a range of different resolutions, refresh rates and colour spaces. Some models support HDCP content, whilst others are not.

Hardware

Common hardware features of AV over IP codec devices are below, but will differ amongst manufacturers and product ranges:
Encoder (Transmit) Interfaces
Decoder (Receive) Interfaces
HDMI Input
HDMI Output
HDMI Loop Out
DisplayPort Input
DisplayPort Output
Analogue Audio Input (Balanced and Unbalanced)
Analogue Audio Output (Balanced)
RJ45 1GbE Ethernet (PoE)
LC or SC 10Gbps SFP+ Fibre
RS232 (For control of connected device)
Infrared (IR) (For control of connected device)
USB Interfaces (Media Storage, HID – Human Interface Device)
DC Power
Form-factor designed to be mounted in the following situations:
  • Behind display
  • On rack shelf
  • Underside of table
  • Some floor box models available
  • Modular card-based chassis models are also available from a variety of manufacturers

Common Software Features

Common software features found in hardware encoder and decoder endpoints include:
  • Encoders/decoders may be typically either:
    • Open standard codec (H.264, H.265, or Motion JPEG 2000) may be compatible across various manufacturers; or
    • Proprietary codec requiring encoders and decoders to be from the same manufacturer, and same product range
  • Network latency (end-to-end network transit)
    • no greater than 45ms for lip-synced content
    • no greater than 250ms for any other content streamed within a room
    • When streams are viewed outside of the room, higher latencies may be suitable
  • Streams video signals with selectable resolution, refresh rates and colour space up to and including 4K60 with 4:4:4 subsampling
Common control and management features of AV over IP hardware codecs:
  • Embedded web browser configuration interface (navigate to codec device IP address to access management pages)
  • Remote management features
  • Customisable network and security configuration
  • Device discovery via Bonjour protocols
  • IP Control
  • RS232 Control
  • Supports 802.1x Network Access Control
Additional software features (platform-dependent):
  • Decoder device may accept multiple video streams to display on-screen concurrently (Picture-in-Picture)
  • Flat panel display video wall image processing
  • AES67 audio over IP standard support
  • Audio de-embed from video stream (audio breakaway)
  • Audio embed into video stream
  • Dynamic text overlay

Management

Function

Management of AV over IP devices can be handled in multiple ways, and a combination is often required for the commissioning, support and user-driven control of AV content.

Vendor Software

Vendor-specific software should be available for download that allows direct communication between encoders/decoders and a computer or server via a network.

Web Browser Access

Encoders and decoders should be accessible via web browser (HTTPS) for configuration of the majority of settings.

AV over IP Management Device

Specific AV over IP management devices are often available from vendors for control and management of large deployments, creating a single point of access to multiple encoders and decoders.
AV over IP management is defined as follows:
  • Software running on computer hardware to communicate with encoders/decoders connected to the network
  • Management device may be:
    • A function of the AV control processor deployed for the AV systems; or
    • A device deployed specifically for managing the AV over IP system; or
    • A software package installed on standard server computer hardware
  • Connects to the network via Ethernet interface
  • Controls the operation of the codec devices
  • May facilitate the bulk configuration, or automatic configuration of endpoint devices connected to the network
  • Control protocol/API compatible with third party control systems

Hardware

Common hardware features of AV over IP management:
  • Ethernet interface
  • Additional Ethernet interface for remote administration when video is using an air gapped switch.
  • Device types:
    • AV control processor device
    • AV over IP specialised management device
    • Standalone Room Controller
    • Centralised Control Server

Software

Common software features of AV over IP management:
  • Embedded web browser configuration interface (navigate to device IP address to access management pages)
  • Remote management features
  • Auto-discover codecs connected to local network
  • Manage configuration of codec devices over network
  • Supports 802.1x Network Access Control
  • Proprietary software features (platform-dependent):
    • Secure AES-256 encrypted connections
    • Active Directory / LDAP authentication
    • Remote management via secure shell (SSH) authentication

Network Infrastructure

Function

Network Infrastructure for AV over IP systems is defined as follows:
  • Active (network switches, routers, firewalls, et al) network components that compose a network
  • Passive (cabling, outlets, patchbays, et al) network cables andconnections that compose a network
  • Establishes network communications between encoding devices, decoding devices, and management control software / hardware
  • Manages network traffic, routing, and security

Network Architecture Options

Common network architecture options for AV over IP:
  • Network may be:
    • Dedicated network switch(es) air-gapped from other network traffic; or
    • Dedicated AV over IP VLAN, with video traffic restricted to the local subnet, and administrative access to control and management functions possible from other subnets.
    • Converged network (mixed use) that may allow select network traffic to reach other production AV over IP VLANs
  • Discuss with your network team to request an allocation of multicast address space that is dedicated for AV over IP traffic only within your institution
Note: Refer to the product-specific AV over IP deployment guide for detailed network architecture options

Network Cabling Requirements

Network cabling requirements for AV over IP:
Network Speed
Cabling Requirement
1G Network
  • Category 5e or 6 Ethernet cable rated for 1 Gbps network speed
  • Ethernet IEEE 802.3 cabling and connectivity standards
10G Network
  • Single-mode or Multi-mode fibre optic cable rated for 10 Gbps network speed
  • Fibre optic IEEE 802.3 cabling and connectivity standards
  • Category 6A or 7 Ethernet cable rated for 10 Gbps network speed at 100m
  • Category 6 Ethernet cable rated for 10 Gbps network speed at 55m
  • Ethernet IEEE 802.3 cabling and connectivity standards

Network Switch Hardware Requirements

Typical network Switch Hardware requirements for AV over IP:
  • Layer 2+ switch (if keeping encoders & decoders within a subnet)
  • Layer 3 switch (if routing encoders & decoders outside of a subnet)
  • 1 Gbps data throughput capability for each interface connected to an encoder or decoder, unless video data is required
  • Non-blocking switch that allows all ports at full capacity without any backplane limitations
  • Supports unicast, multicast, and broadcast messaging across the network
  • IGMPv2 / IGMPv3 features
  • 802.1x Authentication features
  • PoE (Power over Ethernet), PoE+, UPoE (if encoders / decoders may be powered via Ethernet interface)

Network Switch Configuration

Typical network protocols used for AV over IP:
Protocol
Configuration
802.3az Energy Efficient Ethernet (Green Ethernet)
Disabled
IGMP Snooping
Enabled
IGMP Querier
Enabled
IGMP Immediate Leave (Fast Leave)
Enabled
Multicast Forwarding (Multicast Filtering)
Enabled
QoS (Quality of Service)
Enabled
Note: Refer to the product-specific AV over IP deployment guide for detailed network switch configuration

Network Router / Firewall Configuration

Typical network protocols used for AV over IP:
Protocol
Configuration
IGMPv3
Enabled
PIM (Protocol Independent Multicast)
Enabled
QoS (Quality of Service)
Enabled
DHCP
Enabled
HTTP (TCP/UDP Port 80)
Allow
HTTPS (TCP/UDP Port 443)
Allow
SSH (TCP Port 22)
Allow
RTP (Real-Time Transport) UDP Traffic
Allow
RTSP (Real-Time Streaming Protocol) UDP Traffic
Allow
Note: Refer to the product-specific AV over IP deployment guide for detailed network router and firewall configuration
Last modified 11mo ago