[asterisk-dev] DTLS setting impacts encryption setting

[Daniel Pocock]

This was on -users, but it appears all the DTLS discussion is on -dev so
I'm reposting it...


If I understand correctly, setting

   encryption=no

means that Asterisk will make outgoing calls without encryption, but
will be happy to accept incoming calls regardless of whether the caller
wants encryption or not (that is how it has been working for me anyway)

If encryption=yes, then Asterisk not only uses encryption for the
outgoing calls but it will refuse to accept incoming calls unless they
use encryption too.

If I have

   encryption=no
   dtlsenable=yes

the DTLS support works but Asterisk will no longer accept incoming calls
using regular RTP/AVP.  These messages appear in the console and the
call is rejected with code 488:

[Jan 28 11:08:42] WARNING[24673][C-00000009]: chan_sip.c:10496
process_sdp: Processed DTLS [FALSE]
[Jan 28 11:08:42] WARNING[24673][C-00000009]: chan_sip.c:10529
process_sdp: We are requesting SRTP for audio, but they responded
without it!

I realise not everybody would set encryption=no in this situation, I'm
simply trying to make it work for all possible callers to the
SIP5060.net test numbers at http://www.sip5060.net/test-calls

Is this a bug or is there some reason that DTLS-SRTP can't allow the
older behavior to continue?