Short mdns resolve timeout causing WebRTC connection failure on local network

[yiufaicheng-iginno]

Hi,

I am facing a problem where the frontend, using JavaScript, connects to a Python aiortc WebRTC server. The connection works fine with a STUN server, but fails when no internet access is provided. The issue is similar to the one described in the following GitHub issue: Webcam example without Internet connection.

Upon investigation, I discovered that the RtcIceCandidate is in mdns format and uses mdns to resolve the hostname. The ice.py code snippet below illustrates this:

if mdns.is_mdns_hostname(remote_candidate.host):
    mdns_protocol = await get_or_create_mdns_protocol(self)
    remote_addr = await mdns_protocol.resolve(remote_candidate.host)
    if remote_addr is None:

The resolve timeout in the mdns protocol uses a default value of one second. However, on my computer, I have several network adapters (at least 4, including virtual networks such as VirtualBox and VMware) that can cause the resolution to take more than one second. I solved the problem by changing the timeout to 5 seconds.

I would like to know if there is a way to customize the resolve timeout in aioice so that it can be based on my situation to use the appropriate timeout.

Thank you.