Re: [rtcweb] draft-kaplan-rtcweb-sip-interworking-requirements-00

[Hadriel Kaplan <[e-mail]>]

On Oct 25, 2011, at 5:50 AM, Iñaki Baz Castillo wrote:

> Let me a question about section 4.2.2:
> 
> ----------------------------
> 4.2.2     SRTP Termination    [...]   It should be noted that if SRTP
> is required to be used for every    call by RTCWeb but the [SDES] key
> exchange model cannot be used on    the RTCWeb side, then the
> Interworking Function likely has to    terminate SRTP from RTCWeb even
> if the SIP-domain supports SRTP,    because [SDES] is the most
> commonly used form of key exchange in SIP
> today.------------------------------
> 
> I was not aware of such limitation. Could you please point me to some
> draft or mail thread in which that limitation (SDES key exchange model
> cannot be used on the RTCWeb side) is explained?

There were discussions at a previous meeting and an email thread a while back on whether (1) SRTP should be mandatory to use, and (2) on whether it must be dtls-srtp key exchange.

I believe one thread on this was started here:
http://www.ietf.org/mail-archive/web/rtcweb/current/msg00460.html

I don't know if a conclusion/consensus was reached. Thus I wrote that section of the draft assuming it could go either way. 

-hadriel