Can't Answer in RN Webrtc app when Freeswitch calls


Anyone doing RN WebRTC + Freeswitch integrations? Having an issue when answering calls made from Freeswitch to RN Webrtc App. Freeswitch complains something about DTLS and fails handshake. Calls in the other direction are ok though. Btw, what version of DTLS 1.75.2 (M75) uses?

A penny for some thoughts…


That’s weird, it’s the first time I’ve heard about DTLS problems with this plugin, so my first suspect would be FS. This plugin uses DTLS 1.2, IIRC.

Hi Saghul, thanks for the reply.

I don’t really understand DTLS yet but it seems to me that in some cases the Client Hello sent by the plugin doesn’t use DTLSv1.2 and Freeswitch which also uses DTLSv1.2 on the version we’re using rejects the setup. Weird thing is that this only happens when the React App answers a call. Making calls is ok…

I can share some pcaps.

Yeah, some pcaps would help I think.

Will send you through the DM conversation asap.

Sent. :slight_smile:

hi @saghul

Seems this is some DTLS library error (OpenSSL, SSL_ERROR_SSL, the worst kind, lol). Is there any way of tweaking some parameters on the SSL library used in the module? If so do you see this making any diference?

Best regards.

I don’t really know, TBH. libWebRTC uses BoringSSL, but it’s initialized internally.

That said, we have used libWebRTC with this plugin for years with zero such bugs with any browser, so I’d start to debug on the FS side, which, coincidentally will probably be easier.

Thanks @saghul, we’ll try.

@saghul one question. Is the libWebRTC you speak of the same lib that browsers use? how does that work? You know?

Yes, it’s the same library. Regarding DTLS, I know browsers still support 1.0 for now, but Chrome is going to drop support for DTLS 1.0 and 1.1 in version 80.

Weird that the thing works with any browser. What could be the difference? :expressionless: