In here, we will configure two LSFGateway nodes to send an RTP video stream from Node A to Node B, over Internet using UDP data channels, as shown in the diagram below. 

Prerequisites:

First, please make sure you have installed three lsfgateway nodes and that you have access to the LSF Manager web app, following the instructions in the Config Prerequisites page.

Create the empty node configs

• Log in to LSF Manager.
• Navigate to Administration → Node Configuration.
• Click Add Node Config.
• In the dialog, enter your node_id “node-a” and hit Add.
• Also do the same to create another config for “node-b” and “node-c”

The result looks like something like the screenshot below:

Edit the config for “node-a”

In this example, node-a is configured as the input side of the video stream. It will have a WebRTC data-channel connection to node-b and node-c is the output node. 

• Navigate to Administration → Node Configuration.
• Find node-a in the list and click the Edit button. It will open the node configurator page

When configuring the node for the first time, the Configurator adds a simple example configuration which is the one you see when opening the page. 

Our video transport configuration is very similar to the default config. Therefore, we just need to make some small modifications to the config above. 

Configure node-a, video input socket:

Click Edit on the socket and configure the values as shown below

• Socket ID: we need a unique label. We call it “socket_video”
• Type: our video feed is a UDP stream
• Bind IP: This is the input IP and Port number that receives the video feed from the local network. We can use a multicast address to join an IP multicast stream or we can simply use a unicast address to bind to a unicast stream. In here, we use a unicast 0.0.0.0 address to bind to any IP source. The IP address must follow by a port number. In our case, the socket is configured to receive anything sent to port number 7111. So our configuration is: “0.0.0.0:7111”  
• Destination IP: used for output, leave it empty.
• Blue input From: used for output, leave empty.
• Red input From: used for output, leave empty.
• Threshold: used for output, leave empty.
• Hitless buffer: used for output, leave empty.
• Max In: used for output, leave empty.

Configure WebRTC Data Channels

In here, we are configuring the WebRTC Peer Connections and the data channels between node-a and node-b and node-c

Navigate to WebRTC Data Channels and click + Edit Peer info

Fill in the fields:

• Peer ID:  A unique identifier that must be the same on both ends of the peer connection. We name it “peer_node_a_b”
• Remote Node ID: The Node ID of the remote node which is “node-b” 
• IP Interface: Optionally, provide an IP address (or IP:Port such as 10.0.0.1:5001) to tunnel all WebRTC STUN server traffic through the specific IP and port number.  But we don’t need it at this stage so leave it empty.

Once the Peer Connection is configured, you can add Data Channels within the WebRTC connection. Typically, you configure one data channel for each IP flow. Fill in the following:

• Datachannel ID: must be unique, “dc_udp_video_a_b”
• Ordered: ‘true’ to guarantee in-order delivery (note that this may add retransmission delays)
• Max Packet Life: (used for unordered only) Maximum time to wait before dropping a late packet. Leave it as it is.
• Max Retransmits: Maximum number of retransmission attempts before dropping a message. Use “3”.
• Channel Input From: This is the important part, telling the data-channel to receive its data flow from where? In our case, it needs to receive the flow from the video udp socket we created above: “socket_video”

You can experiment with ordered and unordered, max retransmission and max packet life. 

Now, we also need to create a WebRTC Peer config to connect between node-a and node-c. Click on Add New Peer to add a new Peer and data-channel. Use below values.

• Peer ID:  “peer_node_a_c”
• Remote Node ID: The Node ID of the remote node which is “node-b” 
• IP Interface: leave empty

Click on Add New Data CHannel to add a new data-channel. Use below values.

• Datachannel ID: must be unique, “dc_udp_video_a_c”
• Ordered: ‘true’ 
• Max Packet Life: 500 (doesn’t matter if ordered is true)
• Max Retransmits:  “3”
• Channel Input From: It does also receive its flow from the video udp socket we created above: “socket_video”

Now we are ready with the configuration of “node-a” which should look like below:

Make sure to save the file on the server by clicking on Save.

Edit the config for “node-b”

node-b is configured as the output side of the video stream. It will have a WebRTC data-channel connection to node-a. It receives the data from node-a and outputs it on a local UDP socket.  

Configure WebRTC Data Channels

In here, we are configuring the WebRTC Peer Connections and the data channels between node-a and node-b

Navigate to WebRTC Data Channels and click + Edit Peer info

Note that the Peer ID and Datachannel ID must be identical with the ones used when you configured node-a. 

Fill in the fields:

• Peer ID:  must be identical to the ID we configured in node-a. Both sides must be the same “peer_node_a_b”
• Remote Node ID: The Node ID of the remote node which is “node-a” 
• IP Interface: don’t need in here. Leave empty

Once the Peer Connection is configured, you can add Data Channels within the WebRTC connection. Typically, you configure one data channel for each IP flow. Fill in the following:

• Datachannel ID: must be identical to the datachannel id used in node-a, “dc_udp_video_a_b”
• Ordered: ‘true’ to guarantee in-order delivery (note that this may add retransmission delays)
• Max Packet Life: (used for unordered only) Maximum time to wait before dropping a late packet. Leave it as it is.
• Max Retransmits: Maximum number of retransmission attempts before dropping a message. Use “3”.
• Channel Input From: None. It doesn’t receive any input. 

Configure node-b, video output socket

Use the parameters as described below

Socket ID: we need a unique label. We call it “socket_video”

Type: our video feed is a UDP stream

Bind IP: leave empty.

Destination IP: Use whatever IP you are testing with. Could be local interface or another IP address and port number. Could also be a multicast IP address if you with to output the video as a multicast stream. 

Blue input From: The input flow to the socket is the webrtc data channel dc_udp_video_a_b.

Red input From: used for output, leave empty.

Threshold: used for output, leave empty.

Hitless buffer: used for output, leave empty.

Max In: used for output, leave empty.

The configuration for node-b should look like below.

Edit the config for “node-c”

node -c is very similar to node-b. Only differences are the WebRTC ID, Datachannel ID and the  socket ip address used to output the video stream. 

Configure WebRTC Data Channels

• Peer ID:  must be identical to the ID we configured in node-a. Both sides must be the same “peer_node_a_c”
• Remote Node ID: The Node ID of the remote node which is “node-a” 
• IP Interface: don’t need in here. Leave empty

Once the Peer Connection is configured, you can add Data Channels within the WebRTC connection. Typically, you configure one data channel for each IP flow. Fill in the following:

• Datachannel ID: must be identical to the datachannel id used in node-a, “dc_udp_video_a_c”
• Ordered: ‘true’ to guarantee in-order delivery (note that this may add retransmission delays)
• Max Packet Life: (used for unordered only) Maximum time to wait before dropping a late packet. Leave it as it is.
• Max Retransmits: Maximum number of retransmission attempts before dropping a message. Use “3”.
• Channel Input From: None. It doesn’t receive any input. 

Configure node-b, video output socket

• Socket ID: we need a unique label. We call it “socket_video”
• Type: our video feed is a UDP stream
• Bind IP: leave empty.
• Destination IP: Use whatever IP you are testing with. Could be local interface or another IP address and port number. Could also be a multicast IP address if you with to output the video as a multicast stream. 
• Blue input From: The input flow to the socket is the webrtc data channel dc_udp_video_a_c.
• Red input From: used for output, leave empty.
• Threshold: used for output, leave empty.
• Hitless buffer: used for output, leave empty.
• Max In: used for output, leave empty.

The result looks like below:

Start the lsfgateway nodes

At this stage, we are ready with creating the configuration for the nodes. Now it’s time to test the video flow. 

Make sure you have your Account ID and Secret Key that is required to start the lsfgateway nodes. If you don’t have them, you can create new ones.

• Log in to LSF Manager.
• Navigate to Administration → Network Keys.
• Click Add Account ID.

Start node-a

Start node-b

Start node-c

Check monitoring status of the nodes

To check status, do the following. 

• Log in to LSF Manager.
• Navigate to Monitoring → Active Nodes.

If all nodes are active, you will see them in the LSFManager as shown in the screenshot below:

Select Monitor, to see node status. The WebRTC channels (in green), show the status of the peer connections. If the connections are up, you can see a small tick in front of each data-channel id as shown below.  

Test video transport

Now it’s ready for the video test. One easy tool to use is VLC media player. 

Example of setting up video generator to send to the input on node-a: 

And to play the video on node-b and node-c receiving sides, as an example, you could configure the VLC player like below: