In this article, we show an overview of the main components, programs, and elements involved in getting audio from your Radio Automation System (RAS) to the end listener.
Below is a simplified diagram of the Triton streaming architecture.
Lets examine each part, in the order of the flow of audio data from the encoder to the listener.
Radio Automation System (RAS)
If you're a live streaming customer of Triton Digital, you are probably familiar with this component. It is usually located at your physical radio station (for terrestrial stations) or in a data centre somewhere (for virtual online-only stations). Regardless of the actual software used, two sources of information flow from the RAS: audio and metadata.
Audio is usually sent by cable to the encoder, and can be digital or analogue.
Metadata includes, among other things, the "what is playing" information and "cue points" for marking ad breaks, is usually sent digitally from the RAS to the encoder.
Encoder/Station Manager (SM)
For regular terrestrial stations, the encoder, often referred to as the "streaming computer," is a piece of computer hardware that usually resides at the radio station, typically in the same building as the RAS. Its purpose is to run Triton's Station Manager (SM) software. SM is the origin of the stream; its purpose is to take the audio and metadata sent by the RAS and digitally encode it into the streams required by each station (AAC/MP3/various bit rates).
Audio usually arrives via the computer's physical or virtual audio card.
Metadata usually arrives to the encoder via the computer's internet connection (usually an Ethernet cable).
SM can stream one or multiple stations at once, depending on the hardware used. Our customers usually opt to also have backup computers in case of a critical failure of the main encoder. The architecture of these setups varies widely from customer to customer. Your local Audio Engineer should be very familiar with its intricacies.
Once encoded, the streams leave SM via the computer's internet connection and are sent across the internet to the Triton Streaming Network.
The Internet
Ubiquitous and unavoidable, the internet is the link that carries the streams sent by the encoder to the Triton Streaming Network. Your internet connection is made of many different links, which begins with your Internet Service Provider (ISP) and often travels through several other backbone ISPs before reaching the Triton Streaming Network.
Triton Streaming Network
The Triton Streaming Network is composed of many points of presence (data centres) around the world. Each station is assigned a pool of possible "entry" points composed of several servers located in the closest data centres.
There are numerous components at play in the Triton Streaming Network that do various things, such as ad servers, data servers, and other components. For the purpose of this article, we will only look at Media Relay, Media Gateway, and Provisioning servers.
Media Relay Servers
The Media Relay (MR) servers are responsible for receiving the stream from the encoder (carried over the internet) as well as carrying the stream between data centres as needed.
Media Gateway Servers
The Media Gateway (MG) servers are the workhorses of Triton's streaming and ad insertion capabilities. These servers are responsible for delivering the streams to listeners as well as injecting the in-stream ads each listener hears. They are the "exit" point of the Triton Streaming Network.
Provisioning Servers
When a listener's device requests the stream from the Triton Streaming Network, the request is first sent to a provisioning server. These servers are tasked with looking at the platform as a whole and selecting the closest active and healthiest MG server for the listener to connect to. The provisioning servers constantly scan the entire streaming network to make sure a listener is not directed to an MG that is in maintenance mode, too heavily loaded, or far from the listener. When a device requests the stream through an official URL, Provisioning will dynamically return a server link for the device to stream from.
We highly discourage our customers from hard-coding any returned link from the provisioning server (links with numbers at the beginning). Triton will not notify its customers when specific servers go into maintenance, are removed, upgraded, or replaced since Provisioning always takes care of removing these servers from its available list. Any integration of hard coded "direct" server links will eventually result in problems, and is done at our customer's own risk.
The Internet (again)
Once again, the streaming signal travels from the Triton streaming network (specifically, the MG) to the listener's device. While there are mechanisms in place to reduce the impact of issues with ISP providers, the stream is still dependant on the internet to be carried to the listener.
The Listener's Device
The listener's device is responsible for requesting the stream, downloading the flow of data at an acceptable rate for consistent playback, and (obviously) playing the audio. Devices come in many forms: smart watches, smart speakers, web players, mobile apps, and even televisions. There is a seemingly infinite number of devices capable of streaming audio, each with their own challenges and limitations.
To help our clients achieve the best possible listener experience, Triton provides a generic web player with each stream, as well as access to Software Development Kits (SDKs) for Web browser, iOS, and Android players. SDKs are actively maintained and updated regularly with bug fixes and improvements. They are free to use by any organization wanting to improve the listener experience when connecting to Triton streams.
We highly recommend that our customers use our official SDKs to build their own players and apps. The SDKs use mechanisms that ensure optimal connection stability as well as the support of metadata and advertising mechanisms necessary to ensure optimal ad revenue.
Other devices use their own proprietary mechanisms to connect to the streams. While Triton tries its best to adhere to streaming standards, these manufacturers are ultimately responsible for the compatibility and performance of their devices.