hubertlepicki
Elixir server for WebRTC data channels (or other UDP-like channels)
I am trying to build something using Phoenix channels, and as great as they are, I am hitting a wall with something.
Basically, I need to send data to server in “fire and forget” manner. I may also get occasional messages from the server. I am not interested in retries, failures, and correct order of arrival of my (or server’s) messages.
I need a UDP-like connection, and Phoenix channels are TCP-like.
I know WebRTC data channels can be put into “unreliable” mode. This looks like what I need precisely, and I tested it browser-to-browser, this will be alright.
But I failed to find any info on how can I integrate that with Elixir on the server. Any ideas?
It’s not a signaling server I need, but a server that would join WebRTC data channel in similar fashion as browsers do.
Most Liked
smpallen99
I’ve done a lot of voice WebRTC with elixir. Typically, the media path for WebRTC is from browser to browser, and the server is not included in the media path unless you need to have the server in the middle of the media path. Phoenix channels are great for the WebRTC signalling portion to setup the media path. I have not used data channels yet, but can’t imagine that they are much different than voice or video.
If you need to anchor the media path on the server, your going to have some difficulties with Elixir/Erlang. Current browsers require that the WebRTC media path use DTLS (TLS over UDP). The last time I checked (6 months ago), there was NO support for DTLS in erlang.
I have a simple Phoenix WebRTC demo project on github you may want to checkout.
Steve
sasajuric
I’m not sure if using Phoenix for accepting UDP makes sense. Phoenix endpoint is powered by Cowboy, so TCP is always underneath. UDP is connectionless, so even if it can somehow be integrated directly into endpoint, I think it would be a needless complication.
If the system needs to handle UDP next to TCP traffic, I’d just start a separate process powered by gen_udp. I think it can even listen on the same port as the endpoint, as the networking protocols are different.
michalmuskala
@hubertlepicki While it might be possible to do this with phoenix, it might not be the best idea - I forgot to add that to my response 
So I fully agree with you here.
@sasajuric I don’t think the channel has to be started by the cowboy. The transport implementation controls this entirely.
Qqwy
It may be worth noting that DTLS-support now is in beta in OTP20.
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
We build reliable cloud platforms for business-critical systems.
Categories:
Sub Categories:
Forums
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Practical resources that improve the lives of professional developers.
Producing high quality Elixir screencasts since 2017.
Enabling companies to succeed by building software people love.
Courses that'll move you from confusion to "Aha, now I get it!"