Privacy Enhanced RTP Conferencing
IETF 99
Session 2017-07-18 9:30 - 12:00
Chairs :- Suhas Nandakumar, Nils Ohlmeier

Scribe: Roni Even
Jabber: Matt Miller

Summary
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* draft-ietf-perc-double, draft-ietf-perc-srtp-ekt-diet
  - Cullen presented a new way to do OHB (now in payload), a joint proposal 
    from Sergio and Cullen
  - Presentation also focussed on doing RTP Repair (RTX, RED, Flexfec) in PERC
     —- Idea is to do repair on the double encrypted packet
  - Ekt draft had no technical changes and may need some changes due to the new
    OHB proposal
  - Chairs made the consensus call and there was strong consensus
    on the overall direction of the new OHB proposal as well as the repair
    procedures in PERC
  - Authors to submit new version detailing the proposals.

* draft-ietf-perc-private-media-framework
  - Paul presented on the editorial changes related to PERC key-management & packet
    format.
  - No major open issues.
  - Expected reviews

* draft-ietf-perc-dtls-tunnel
  - Paul presented on the changes related to removal of dlts-id and inclusion
    of the tls-id in the tunnel, make association ID as UUID and other
    editorial changes for better readability.
  - No major open issues.
  - Expected reviews


* Action Items and Next Steps
  - Chairs to confirm the consensus on the list
  - Double Authors to submit updated version.
  - Chairs to setup virtual interim to help progress the decisions
    made in this meeting.



Raw Notes (Roni Even)
Chairs Intro

New Chair – Nils

No comments on milestones



 SRTP Double draft-ietf-perc-double  - Cullen

EKT on Diet draft-ietf-perc-srtp-ekt-diet – Cullen



What is lite – SRTP in SRTP

FlexFEC – usually before encryption

In PERC – before, after or in the middle.

A option after double

B option before – MD cannot do repair

Lite – after E2E before HBH

RED – Magnus asked about RED what happenes with payload type when changing from non red to red in the MD. Need detailed information about how it will work.

Proposal – move obh to payload after header.  – slide 15

Roni – how will the SDP work,

Cullen – no change still original payload since encrypted.

Mo : how does framemarking works. Marker bit is not enough.

Cullen : do we allow SFU to set the m-bit.

Consensus: the M bit can be changed by SFU

Cullen: the bitfield work, maybe from the MD to KD to client.

The proposal: Move OHB information from header extension to payload, use RTX,RED and flexfec as in “A”. DTMF: MD cannot receive DTMF. (Add text as Magnus requested).

Consensus on slide 16 : the WG accepted the direction. Expect verification of the solution for next meeting.

EKT issue (18) – add in to the DTLS EKT messge , the value of bitfiled value for the new Double payload if we make the OHB->payload change.

Cullen : can be by defining multiple protection profiles instead of change as above.

Action: Need to verify using multiple profiles for different bitmaps



 DTLS Tunnel draft-ietf-perc-dtls-tunnel – Paul Jones

TLS-ID – remove the editor note – will be out of scope





PERC Framework draft-ietf-perc-private-media-framework – Paul Jones

Added two appendixes – appendix B will need an update based on the payload structure change.