{"id":27140,"date":"2021-10-22T19:00:49","date_gmt":"2021-10-23T00:00:49","guid":{"rendered":"https:\/\/learncctv.com\/?p=27140"},"modified":"2021-11-29T12:05:18","modified_gmt":"2021-11-29T17:05:18","slug":"multicast-on-axis-cameras","status":"publish","type":"post","link":"https:\/\/learncctv.com\/multicast-on-axis-cameras\/","title":{"rendered":"How to use multicast on Axis cameras"},"content":{"rendered":"

In this article, I explain how to use multicast <\/strong>in Axis cameras<\/strong>.<\/p>\n

Here you can understand how the multicast works and how to test it.<\/p>\n

This is not just theory. I’ve tested video streaming via multicast with my Axis <\/span>P1365 MK II <\/span><\/strong>camera, so you can see some real examples of how it works.<\/span><\/p>\n

The picture below shows an <\/span>Axis camera<\/span><\/strong> using <\/span>multicast <\/span><\/strong>in the <\/span>VLC software.<\/span><\/strong><\/p>\n

\"Axis<\/span><\/p>\n

Axis P1365 MK II on VLC via multicast<\/p>\n

There are different ways you can have your camera working with multicast.<\/p>\n

Keep reading to understand the details (believe me, they are very important<\/strong>).<\/p>\n

Pay attention to the 3 methods described in this article:<\/p>\n

1. Any-source Multicast (ASM)<\/p>\n

2. Source-specific Multicast (SSM)<\/p>\n

3. Always multicast<\/p>\n

>> Important:<\/span><\/p>\n

Let’s get started with multicast for security cameras.<\/p>\n

Multicast and Unicast for security cameras<\/h2>\n

OK,  the first thing we need is to understand how multicast works.<\/p>\n

Let’s compare a network diagram with security cameras using Unicast and Multicast and then discuss how to implement multicast correctly.<\/p>\n

Unicast<\/h3>\n

The following diagram shows an <\/span>Axis camera<\/span><\/strong> ready to send a video stream to two different computers using the traditional method via <\/span>Unicast<\/span><\/strong>.<\/span><\/p>\n

\"Unicast<\/span><\/p>\n

Security camera using Unicast (click to enlarge)<\/p>\n

In this scenario, it’s necessary to send a separate video stream to each computer.<\/p>\n

That’s why we use the name “Unicast<\/strong><\/em>“, which is a 1 to 1 relationship.<\/p>\n

Now, take a look at the following diagram to understand how the camera sends a video stream to both computers in the network using their IP addresses.<\/p>\n

\"Axis<\/span><\/p>\n

Network Diagram: Security camera using unicast (click to enlarge)<\/p>\n

As you can see, the camera established a connection to each computer and streamed the video twice, making it use more resources (bandwidth, CPU, memory).<\/p>\n

This is just a random example where each video stream uses 1Mbps.<\/p>\n

Now imagine more computers in this scenario…<\/p>\n

The camera will run out of resources pretty quickly.<\/p>\n

Here’s where the multicast comes to the rescue.<\/p>\n

Multicast<\/h3>\n

Now let’s take the same scenario and use multicast to send the video stream.<\/p>\n

The following picture shows how the IP camera <\/strong>can communicate via multicast<\/strong>.<\/p>\n

\"Example<\/span><\/p>\n

Axis IP camera using multicast (click to enlarge)<\/p>\n

In this scenario, the camera can send the video stream to a Multicast IP (group).<\/p>\n

The camera sends the video stream to a switch that distributes it to the computers.<\/p>\n

That’s pretty smart, huh? \ud83d\ude42<\/p>\n

Take a look at the diagram below.<\/p>\n

\"Axis<\/span><\/p>\n

Axis camera Multicast (click to enlarge)<\/p>\n

As you can see, the camera sends only one video stream to the switch which and the computers can pull it from there. Now the camera resources are not impacted.<\/p>\n

=> That’s a simplified explanation of how multicast works. There are many more details on the topic, but I intend to make things simple to understand.<\/p>\n

Now, let’s understand the different ways you can use multicast on Axis cameras.<\/p>\n

Multicast on Axis cameras<\/h2>\n

Now, let’s understand the different ways you can use multicast on Axis cameras.<\/p>\n

You can have your Axis camera streaming video to the network.<\/p>\n

1. Any-source Multicast (ASM)<\/h3>\n

The client (computer or other devices) sends a request to the<\/span> Axis camera<\/span><\/strong>, Encoder, or any other Axis streaming device and asks for multicast as the transport method.<\/span><\/p>\n

No multicast-specific network parameters<\/strong> are shared in the first communication between the client and the Axis device. These parameters are negotiated later.<\/p>\n

Here’s a picture that illustrates this process.<\/p>\n

\"Axis<\/span><\/p>\n

Axis ASM (click to enlarge)<\/p>\n

You need to use the software on the client to communicate with the camera.<\/p>\n

Here’s the trace I got from the computer (client) and camera communication.<\/p>\n

(Red <\/span>is the client and Blue <\/span>is the Axis camera).<\/p>\n

\"Axis<\/span><\/p>\n

As you can see, the client initiates the communication by sending an RTSP request to the camera (camera’s IP is 192.168.0.17) on <\/span>port 554<\/span><\/strong> using the <\/span>Live555<\/span><\/strong> streaming media and then waits for the camera to reply.<\/span><\/p>\n

Note that the resolution (1920×1080) and the Frame Rate (15 FPS) are informed.<\/p>\n

The Axis camera responds and informs the Options to control the video stream.<\/p>\n

Since I did not provide the credentials upfront in the command, a message pops up on the screen asking for the username and password. <\/p>\n

As soon as I enter the <\/span>username\/password,<\/span><\/strong> the authentication goes through. The devices can communicate based on how to<\/span> decode<\/span><\/strong> the video stream (provided by the shared SDP file).<\/span><\/p>\n

The communication proceeds, and the camera starts streaming the video.<\/p>\n

2. Source-specific Multicast (SSM)<\/h3>\n

In this method, the multicast <\/span>network parameters<\/span><\/strong> are <\/span>pre-configured<\/span><\/strong> in the Axis camera (or any other Axis device), and the information is shared in the SDP file.<\/span><\/p>\n

The client does not specify the network parameters such as the multicast IP address because the Axis device does this.<\/p>\n

Here’s how the method works…<\/p>\n

\"Axis<\/span><\/p>\n

Axis SSM (click to enlarge)<\/p>\n

There’s a menu in the camera you can change these parameters.<\/p>\n

Just open the setting and go to Plain Config <\/strong>>> Network<\/strong>.<\/p>\n

\"Axis<\/span><\/p>\n

You can find the multicast IP address<\/strong> in the R0 section<\/strong>.<\/p>\n

\"Axis<\/span><\/p>\n

That’s the IP that becomes available as part of the multicast group.<\/p>\n

When using multicast SSM, the camera dictates the IP that will be used.<\/p>\n

See the diagram with the example.<\/p>\n

\"Axis<\/span><\/p>\n

Axis camera multicast diagram (click to enlarge)<\/p>\n

As you can see, the camera sends the video stream to the multicast group.<\/p>\n

Now the camera uses fewer resources to stream the video to the computers. <\/p>\n

Let’s take a look at a practical example using software to connect to the camera.<\/p>\n

How to use VLC to connect to the Axis camera via multicast<\/h4>\n

I told you I could show you some real examples, right?<\/p>\n

So, here I have the step-step to test multicast using VLC.<\/p>\n