How do I design a basic network for my installation?

James Walton

James Walton

ON LX Team

We often get asked for our recommendation of how to best specify networks for standalone entertainment system installations from installers new to networking.

This guide aims to cover the fundamentals of creating a reliable network for an entertainment setup. For advice on more robust, redundant advanced and involved networks get in touch.

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Given the diverse and varying requirements of each installation each device, we always recommend checking with the manufacturers of your hardware for best practices relating to your specific installation. This guide should act as a good starting point to specify key components of your entertainment system installation network.

What is a Network?#

A computer network connects devices as part of a distributed architecture, allowing data to be transfered and commands to be sent between devices.

Information to Gather Before Planning a Network#

When planning an installation, the following elements should be factored in:

Maximum Bandwidth Requirement#

Bandwidth is the measurement of information transfer (measured in bits/second) that can be carried across a network.

It is important to ensure your control system can cater for the highest bandwidth your system can produce to avoid any bottlenecks.

To determine the system wide bandwidth requirement, add all intended network load together alongside factoring in overhead for future system expansion and one-off high bandwidth transfers that may impact the system.

To optimize how data is routed across your network and reduce un-nececary bandwidth usage ensure the network switch you specify contains a feature named IGMP snooping.

In most cases a gigabit network infrastructure should be capable of supporting most entertainment systems. However in some scenarios users may want to increase this when stream multiple HD video feeds over a network.

Maximum Distance Between Devices#

The maximum distance that a conventional network cable can be run between devices is 100m (333ft). If a longer distance is required, it's recommended that intermediary network switches are used to repeat the signal or long distance fiber is used instead of network cable.

DHCP or Static IP Addressing?#

IP adresses are numerical labels assigned to each device on a network. Without an IP address or valid network configuration, a device cannot communicate on a network.

IP adresses are used for identification of devices and it also serves to provide a location of that device on the network, (much like a street address in the real world).

The two key methods of assigning a network address to a device are; manually (by setting a Static IP), or automatically (using DHCP).


DHCP IP's#

DHCP (Dynamic Host Configuration Protocol) is a feature built into virtually all network devices, that allows them to automaticaaly receive a network configuration (IP address, subnet mask and default gateway & DNS) including:

  • Computers
  • Managed Network Switches
  • Lighting Playback Controllers
  • Smart phones
  • Access Points
  • Gaming Consoles
  • PoS Systems
  • ect...

Using DHCP makes a network easier to manage and far simpler from the perspective of an end user when connecting.

For example, on a public WiFi network, if each user had to configure their network settings before they could connect to the internet from a list of free adresses, it would simply not be fesable.


How does DHCP work?#

When a device is turned on and connected to a network that has a DHCP server, it sends a request to the server, after this request reaches it, the server holds an IP address that the device can use and offers it to the device.

When the device receives this network configuration from a DHCP Server it can start communicating with other devices on the network.

A DHCP Server can be either an embeded device, or software service running on a computer to provides quick, automatic and central management and assignment of IP addresses.

In most homes and small businesses almost all WiFi routers have the option to act as the DHCP server. On larger more complex networks, dedicated routers or whole computers may be dedicated to carry out this task.

There should only ever be a maximum of one DHCP server on a network to stop any adressing conflicts.

DHCP hugely reduces the chances that any two devices on a network will have the same IP address. Something that can easily be done when manually assigning, static IP addresses.

A key part of DHCP is the lease time, without it, each new device that joins the network would incramentally get a higher IP address until the router would run out.

Lease time allows allows routers to re-assign IP adresses to devices to fill the gaps left by devices no longer on the network. The lease time can be set to be anything from a matter of minutes on crowded networks to many hours on networks where multiple users are unlikely.


So DHCP sounds perfect for all devices on my installation, right?...Wrong!#

Most entertainment industry protocols use unicast, a method of directing a message or stream of data to a specific IP address).

As mentioned above, without DHCP lease times, your DHCP server would give out IP addresses until your network runs out of IP's. In most cases, when a device has an IP address assigned by a DHCP server, the least time can cause it to get a diffrent IP address each time it joins the network - definately not good when you're trying to unicast to a device on a standalone installation.


Static IP's#

The majority of entertainment industry protocols use unicast, a method of directing a message or stream of data to a specific IP address).

As a rule of thumb, if a device needs to receive a command from another device, it should be set to a static IP.

When configuring a basic network, for a foolproof plan it's reccomended that all devices have the same subnet mask and all IP adresses are in the same range. i.e.:

Device 1:
IP Address - 10.0.0.10
Subnet Mask - 255.0.0.0
Device 2:
IP Address - 10.0.0.15
Subnet Mask - 255.0.0.0
Device 3:
IP Address - 10.0.0.20
Subnet Mask - 255.0.0.0

Summary#

Only use DHCP for networks where non-technical end users are intended to connect, and ensure all devices that are to be constantly connected and should communicate with eachother regularly are set to static IP's in the same range with an identical subnet mask.

Network Switches#

A network switch is a piece of active hardware in any network used to connect multiple devices together. Network switches use what is known as packet switching to forward data between each connected device.

Network switches come in a variatey of form factors with various link speeds, management options, PoE options and port quantities.

There are two key groups that network switches fall under, managed and unmanaged. The type best suited to your installation depends on its requirements:

Unmanaged Network Switches#

An unmanaged switch works without the need for configuration and connects all devices attached to it and repeats any trafic across all ports.

warning
  • Warning as mentioned in the Bandwidth section, if you intend to send video over IP or use other bandwidth heavy applications, ensure the network switch you select features IGMP snooping.

If you have a limited number of ports available, an unmanaged network switch is perfect for expanding the number of devices that can be connected to your network. Main applications for unmanaged switches tend to be to split a single cable to connect to multiple devices in areas far from the main control rack that do not individually require high bandwidth.

As unmanaged switches connect all devices and send the same data to every port attached without any form of routing or filtering, think of using an unmanaged switch as broadcasting the same data to all ports connected.

For this reason it's not reccomended that an unmanaged switch is used as the central hub of your network

Managed Ethernet Switches#

A managed switch allows you to have more control over the network as well as all traffic moving through the device. Managed switches not only offer tools and the means to monitor the network, but also control over network traffic.

This will allow various options to be set, including port speed, virtual LAN's, redundancy, port mirroring, and Quality of Service (QoS) for network traffic prioritization.

Arguably the most important feature to limit bandwidth and processing power on a network switch is IGMP Snooping.

IGMP Snooping is a feature found on most managed network switches. When enabled it only directs network trafic to devices on the network that are specifically listening to it, instead of sending it to all devices in the way that an unmanaged switch would.


When deciding upon a network switch, key considerations include:#

Power Requirements (if using Power over Ethernet (PoE))#

Power over Ethernet is a good option to power devices without the need to install local power supplys all whilst providing a network connection. PoE is used to power devices from WiFi access points to system controllers and adapters to power other devices.

To remotely power and connect an iPad running to a network, connect an iPad inst Ctrl for iPad way to connect an iPad to a wired network switch whilst still providing power for the most reliable installations.

Some cheaper network switches offer Passive PoE as an option. This offers no handshaking or verification that a connected device can receive PoE. For best practice, ON LX recommend only specifying network switches that use active PoE (such as IEEE 802.3AF) when connecting devices.

To calculate the power requirement of your network switch, simply sum the maximum power requirement (in Watts) of each device you intend to power. ensuring that each port can deliver the maximum capacity of each device you intend to connect. For best practice factor in additional headroom to allow for inrush current on power up.

Wired or Wireless?#

ON LX recommends a wired network wherever possible.

If your computer is being used to output video only and is not connected to other entertainment networked devices a single network port is required. Always ensure that your computer has its firewall enabled and your network is secure.

Firewall#

A firewall keeps all internet traffic entering the system both clean and predictable. i.e. if other devices on the wider building network are playing up, or other ArtNet / sACN Sources are on the network that couls spill onto the wider network, a system the firewall protects against this it by only letting certain traffic through.

Introducing a firewall between the building network and control system means we can ensure all connected devices are secure.

Network Layout#

ON LX recommends using wired network infrastructure wherever possible a wired network.

If your computer is being used to output video only and is not connected to other networked devices a single network port is required. - Ensure that your computer has its firewall enabled.

The majority of Art-Net, sACN Dante and other entertainment specific devices are not designed to be connected to the internet.

If connecting to dmx nodes, vision mixers, audio devices or other integral parts of your control system, you should ensure that these are on secure, private network with no internet connection that only trusted users have access to. This will ensure network traffic is both secure and predictable.

If you want to be able to remotely access devices on this network over the internet, the simplest way to do this is to run an remote access software on a computer and connect it to the internet with a secondary wired network connection. - If your computer only has one network port use a USB -> Ethernet adapter.