Hi All, In Chicago, Colin suggested that I look at an ongoing item in the AVT WG that was specifying the use of SRTP with DTLS (draft-ietf-avt-dtls-srtp-00.txt), and see if there were any necessary adjustments that DTLS over DCCP needed to make. Well, I've looked at it and there doesn't seem to be any need to adjust DTLS over DCCP to accommodate SRTP-DTLS. SRTP-DTLS specifies some extensions to the DTLS handshake, but those extensions are transparent to the way encapsulation is done for DTLS over DCCP. It also specifies that flows using SRTP-DTLS switch to SRTP encapsulation after the DTLS handshake and exchange of keying info (including new keys for the SRTP operation). This is also transparent to DTLS over DCCP. Also, I think that DTLS over DCCP is transparent to SRTP-DTLS. The SRTP-DTLS draft makes no explicit mention of underlying transport protocol and it seems to me that the methods specified work with either UDP or DCCP transport. The authors of SRTP-DTLS might consider adding a short informative section on transport protocol issues, but I don't think that's strictly necessary. At any rate, I believe this closes all issues related to DTLS over DCCP (assuming that everyone agrees with my assessment, of course :-)). I'll be sending a new version of the DTLS over DCCP draft with minor editing changes momentarily, and hopefully we can proceed to WG last call on that (chair hat off at the moment :-)). Tom P.
