Re: [MMUSIC] DTLS-over-SCTP, anyone?

[Roman Shpount <[e-mail]>]

I am fine with this language except it should be "address and/or port"
not "IP address and/or port".

Regards,

_____________
Roman Shpount

On Thu, Feb 11, 2016 at 8:06 AM, Christer Holmberg <
[e-mail]> wrote:

> Hi Roman,
>
>
>
> What about the following new section 3.2:
>
>
>
>     “3.2.  Change of Local Transport Parameters
>
>
>
>       If an endpoint modifies its local transport parameters (IP address
>
>       and/or port), and if the modification requires a new DTLS
>
>       association, the endpoint MUST either change its DTLS role, its
>
>       fingerprint value and/or use the SDP 'dtls-connection' attribute with
>
>       a 'new' value Section 4.
>
>
>
>       If the underlying transport explicitly prohibits a DTLS
>
>       association to span multiple transports, the SDP 'dtls-connection'
>
>       attribute MUST be set to 'new' if the transport is changed.  An
>
>       example of such case is when DTLS is carried over SCTP, as described
>
>       in [RFC6083].”
>
>
>
> Regards,
>
>
>
> Christer
>
>
>
> *From:* mmusic [mailto:[e-mail]] *On Behalf Of *Christer
> Holmberg
> *Sent:* 11. helmikuuta 2016 9:09
> *To:* Roman Shpount
>
> *Cc:* [e-mail]
> *Subject:* Re: [MMUSIC] DTLS-over-SCTP, anyone?
>
>
>
> Hi Roman,
>
>
>
> Your suggestion looks good. I’ll take it as a WGLC comment, and add it in
> the post-WGLC version of the draft :)
>
>
>
> Regards,
>
>
>
> Christer
>
>
>
> *From:* Roman Shpount [mailto:[e-mail] <[e-mail]>]
> *Sent:* 10. helmikuuta 2016 22:42
> *To:* Christer Holmberg
> *Cc:* [e-mail]
> *Subject:* Re: [MMUSIC] DTLS-over-SCTP, anyone?
>
>
>
>
>
> On Wed, Feb 10, 2016 at 2:58 PM, Christer Holmberg <
> [e-mail]> wrote:
>
> >>> I think we can add the following to section 7.1 of dtls-sdp:
> >>>
> >>> If DTLS is transmitted over a reliable transport and if DTLS
> procedures for retransmissions are not used, for instance as described in
> >>> RFC 6083 for DTLS over SCTP, then DTLS association MUST NOT span
> across multiple transports. Using 'dtls-connection' attribute with
> >>> an 'existing' value in combination with change of such a reliable
> transport should be treated as an error and DTLS association MUST be
> >>> terminated.
> >>
> >> Your text as such looks ok. But, do we really want to add it as a
> generic restriction in draft-dtls-sdp? Shouldn't it be
> >> specific for DTLS-over-SCTP instead? What if someone defines
> DTLS-over-<new-fancy-reliable-transport> and they DO allow span?
> >
> > The reason multiple DTLS associations cannot span across several SCTP
> association is due to SCTP association handling DTLS packet
> > retransmission and DTLS procedures for retransmissions not being used.
> We can make a generic statement or limit this to RFC 6083
> > only, but I think, stating the reason why DTLS association cannot span
> multiple transports is important.
>
> I agree.
>
> But, again DTLS-over-SCTP is described in draft-sctp-sdp, so I think such
> text belongs there.
>
>
>
>
>
> How about saying the following in draft-dtls-sdp:
>
>
>
> If DTLS is transmitted over a transport that prohibits spanning of DTLS
> association across multiple transports, such as DTLS over SCTP as described
> in RFC 6083, then 'dtls-connection' attribute MUST be set to 'new' every
> time transport is changed.
>
>
>
> And you can put the previous language in draft-sctp-sdp
>
>
>
> This way each draft only specified things relevant to itself.
>
>
>
> Regards,
>
> _____________
> Roman Shpount
>
>
>