Re: [rtcweb] How to determine TLS roles?

[Christer Holmberg <[e-mail]>]

Hi,

>> If I understand correctly, in RTCWEB we are going to use a single DTLS association for two things:
>> 
>> 1)      Key exchange for SRTP
>> 2)      The data channel
>> 
>> Now, this means that there needs to be a generic way to determine the TLS roles.
>> 
>> In WEBRTC, how are the TLS roles determined?
>
> That was the subject of a rant of mine.
>
> I think the correct answer is that the party that ends up being IceControlling then becomes the DTLS client. Typically the initiator of a session is IceControlling. 
>
> However the recent addition of
> a=setup:passive
> to chrome's SDP clouds the story somewhat, allowing an IceController to say that it is DTLS passive and allow the non-initiator to be the DTLS client.
>
> Ostensibly this is to support early media - where the receiver of a call wishes to send media before the initiator does.
>
> As I said (rather intemperately) this added complexity is not worth the benefit.

I think that it should be possible for a JS App to explicitly set the roles.

Because, when SDP O/A is used on the wire, there are specified rules on how the roles are determined. But, some other on-the-wire protocol may have different rules.

Regards,

Christer