WebRTC: peer connections limit?

Question

How many peer connections can I create on a single client? Is there any limit?

Answer 1

I assume you've arrived at 256 experimentally since there is currently no documentation/specs to suggest it. I don't know exactly how things have changed since 2013, but currently, my own experiments cap out at 500 simultaneous connections per page. As far as I can tell, Firefox has no such limit.

The real limit, according to Chromium source code is 500 (source). As far as I can tell, there was no limit before this was implemented (source) even going as far back as the WebKit days.

I think one reason that it can be tricky to keep track of is that Chrome (and FF for that matter) have always been bad at the garbage collection of dead connections. If you check chrome://webrtc-internals (FF equivalent: about:webrtc), there will often be a build-up of zombie connections that count towards the 500 limit. These persist until you manually destroy them, or close/refresh the page. One way to work around this is through your own heartbeat implementation or using the signalling server to notify of peers disconnecting such that other peers can destroy their connection (although this requires a persistent connection to a signalling server).