Re: Improvements suggestion for DataChannels

On 5/21/2016 7:51 AM, Cristian Lorenzetto wrote:
> I m working for validating the sdp offer based on authorizations but 
> for datachannels
> i can t see in sdp how many data channels are offered and what are 
> their id /labels(i tried either in chrome either in firefox). I think 
> it is a very important missing in sdp and a possible hole in security.

Per the specs this is not negotiated in SDP; if it was negotiated then 
opening channels would become very slow and very heavy-weight. Right now 
opening (and closing) channels is 0 RTT normally.

The initial number of channels at one point was negotiated in SDP, but 
since it was decided to set it to the max of 65534 IIRC (though I'll 
note no browser currently does so due to memory being wasted by the 
stack; Firefox still includes code to renegotiate (at the SCTP level) to 
larger number of DataChannels, but I think Chrome does not).

-- 
Randell Jesup -- rjesup a t mozilla d o t com
Please please please don't email randell-ietf@jesup.org!  Way too much spam