multiple RTCDataChannels

[MarAdvo]

After playing around with the p2p connection using the RTCDataChannel i noticed that my RTCPeerConnection is creating an extra instance of RTCDataChannel when connecting. The connection does however not work if i do not create an instance of RTCDataChannel before the connection myself.
This leaves me with two seperate RTCDataChannel instances.

I was expecting to use it like this

this.DataChannel = await this.PeerConnection.createDataChannel(myLabel);
this.DataChannel.onmessage += (RTCDataChannel dc, DataChannelPayloadProtocols protocol, byte[] data) =>
{
    // message handling
};

But to my surprise, this event never fired.
The connection is open and the message gets received (onopen event fires and message was checked with wireshark).

After looking into it i tried subscribing to the ondatachannel event of my RTCPeerConnection and to my surprise the data channel passed in this event is a different instance than the one i created. Looking into the RTCPeerConnection at this point reveals that there are in fact two data channels in its DataChannels collection, both with the same label.

My questions here are, why are there two DataChannels with the same label?
Which one should i listen to to receive messages?
If I should only listen to the automatically created one can i dispose of the first one i instantiated?
Why is it necessary for me to create a data channel if another one gets created automatically (without instantiating my own the connection does not work at all)?
Am i completely missing the point?

I would really appreciate to get a deeper understanding on how data channels are implemented here, thanks.

To see what i am talking about you can start the example project WebRTCGetStartedDataChannels and set a breakpoint inside the ondatachannel event handler. Add a variable like var myPc = pc and look at the data channels collection. There are two data channels.

---

More weird behaviour:
This code here works somehow. Even though the event listener is set on the first data channel.

this.DataChannel = await this.PeerConnection.createDataChannel(myLabel);

// only gets set once. BEFORE second data channel exists
this.DataChannel.onmessage += (RTCDataChannel dc, DataChannelPayloadProtocols protocol, byte[] data) =>
{
    // message handling
};

this.PeerConnection.ondatachannel += (RTCDataChannel dataChannel) =>
{
    // this gets called AFTER setting onmessage listener
    bool same = this.DataChannel == dataChannel; // is always false
    this.DataChannel = dataChannel;
};

[ha-ves]

Sorry, not sure if I'm following correctly, since I didn't observe duplicated data channel behavior, they are correctly "dc1" (from JS rtcpeer) and "test" (from sipsorcery rtcpeer).

[MarAdvo]

Well thanks to this I just realized that both peers are using the same label. My logic mistakenly created the same label for both peers making it look like duplicate data channels. My bad, thanks for the help!