If you are conversant with streaming platforms, then you must have come across RTMP Streaming. Then, you must be wondering, what is RTMP and how does it work? What is an RTMP server? While RTMP may just appear as a messaging protocol, there is more to what it is and how it works. Here, we shall be explain everything you should know about RTMP streaming and how it works.

At 5centsCDN RTMP protocol is mainly used for ingesting purposes like you can use an encoder such as OBS to ingest the video stream to the 5centsCDN origin server. Simulcasting / Multistreaming is another implementation we use RTMP to publish the stream to Facebook, YouTube, or many other social media platforms. We also use RTMP protocol for internal replication and replicating the stream to transcoding, and recording servers.

RTMP Protocol Explained

Real-Time Messaging Protocol is a protocol that can be used to stream video and audio. It was acquired by Adobe and has since then been available for public use. Many users find this streaming platform very helpful because it has several variations. The variations of these platforms include RTMPS, RTMPE, RTMPT, RTMFP.

Though many users have found RTMP Streaming very helpful, it is primarily used for three different purposes.

• For live streaming
• For adaptive bitrate streaming; and 
• To fast forward video and audio while it is being played.

How Does RTMP Streaming Work?

RTMP works such that it allows users to several independent virtual channels. By making use of RTMP Streaming, you can access audio and video from two different channels simultaneously. This is made possible by a 3-step process that includes the handshake, the connection, and the stream. Let’s discuss these processes in detail.

• The Handshake

RTMP streaming starts by establishing a TCP connection with the RTMP server. It does this through a handshake system of three packets known as chunks. The handshake is done between the client or user and the server such user is trying to access. The client initiates the process by sending a packet to the server. This packet informs the server of the protocol version used by the client. The client immediately follows this up with another packet containing a timestamp.

The server, replying, sends an echo of the packet with the timestamp informing the client of the time it received it. When the client gets this, the client replies with a final packet of the timestamp which the server acknowledges and returns. After the packet exchange is completed, the handshake process ends and ushers in the connection stage.

• The Connection

The connection stage comes after the handshake stage and it is also between the client and the server. Here, the client and server establish a connection through a message format known as Action Message Format (AMF). The client sends a connection request to the server. The server acknowledges the connection request, verifies it, and accepts it. When this is done, the connection stage is deemed as completed.

• The Stream

The final stage is known as the stream. To arrive at this stage before establishing an RTMP connection, the client and server must have gone through the handshake and connection stage. At the stream stage, the client can stream a video or audio and do so at the same time. To do this, the client sends three messages (createStream, ping, and play) to the server. When the server receives this message, it allows the client go on with the streaming process.

Going through these three processes is not just how RTMP streaming works, but also why it stands out from other platforms.

How to Create a Real-Time Messaging Protocol Live Stream

To effectively create a real-time messaging protocol live stream, you need software known as Simple-RTMP-Server. This software needs to be installed on the server that your phone runs on. In the absence of a server that can host this software, you can make use of a third-party provider. One of the best providers that you can use is ManyCam. Considering that there has to be an interaction between the client and a server, a server to host the streaming software is very important. Once you have the server, you can connect it to a content delivery network and have the RTMP live stream created.

5centsCDN makes this process much easier as we have a suite of RTMP protocol supported media server in our CDN infrastructure. So to make it you can ingest your video and audio content by creating streaming ingest points on our CDN. Here to create a ingest and push the RTMP streams and you can playback as RTMP, HLS, or DASH.

The challenge you may experience setting up the RTMP live stream this way is the possibility of increased latency. To solve this problem, you can use CDN such as 5centsCDN or EdgeCompute or bare metal dedicated servers or cloud instances with Digital Oceans.

Leveraging RTMP for Live Streaming

To leverage RTMP for live streaming, you need a media server. Your choice of media server depends on different factors, this is where 5centsCDN makes things easier. Some of the factors that you should consider when choosing a media server is the length of the audio or video, its quality, and the responsiveness of the media server. Not all media servers can be installed on any server. You should always consider a cost factor as this is something that goes up to $150+ per month, whereas you can deploy an RTMP streaming service on 5centsCDN with ease as low as $4.5 per month.

After deciding on the media server that works for you, run it to make sure the streaming engine ingests an RTMP live stream. After doing this, you can configure CDN to pull one stream and restream or packetize into different other protocols such as HLS or DASH. A connection is then created that allows traffic to move from your CDN to the client. Why use a CDN is simply because you can scale and ensure the best network latency which ensures the best end-user experience.

RTMP streaming is the solution for many users who need the means to stream audio and video on different networks simultaneously. As discussed above it works in a simple 3-stage process that helps you understand how a connection is established between a client and the server. While this works best when you are streaming already recorded audio and video content, you can still leverage RTMP for live streaming by running on virtual machines to reduce the costs of latency.

Some of the use cases:

1. RTMP is available as an output protocol in most IP cams
2. RTMP streams are taken as the input source in the most encoder
3. OTT/broadcasters accept RTMP streams in-order restream the stream using their own infrastructure

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