Re: [rtcweb] New Version Notification for draft-jesup-rtcweb-data-01.txt

Michael Tüxen <Michael.Tuexen@lurchi.franken.de> Fri, 11 November 2011 17:02 UTC

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Date: Fri, 11 Nov 2011 18:01:57 +0100
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References: <20111031211134.8188.49554.idtracker@ietfa.amsl.com> <4EAF64FF.8020101@jesup.org> <02485FF93524F8408ECA9608E47D9F2007CACFFAC2@nambx05.corp.adobe.com> <474200CA-F509-438B-A9CD-71742F4AF6B7@lurchi.franken.de> <CABcZeBOEUseuR-dHkxxnan1Gy0aKG+07DSTJAGzOt7ii_2aw3A@mail.gmail.com>
To: Eric Rescorla <ekr@rtfm.com>
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Subject: Re: [rtcweb] New Version Notification for draft-jesup-rtcweb-data-01.txt
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On Nov 11, 2011, at 3:51 PM, Eric Rescorla wrote:

> On Fri, Nov 11, 2011 at 5:15 AM, Michael Tuexen
> <Michael.Tuexen@lurchi.franken.de>; wrote:
>> Hi Michael,
>>>  o DTLS and SCTP handshakes must be performed serially (no matter which order they happen in), which increases the number of round-trips necessary to establish communication.
>> That is correct. SCTP adds one RTT to whatever DTLS is requiring.
>> So when using SCTP/DTLS/UDP, DTLS needs 3 RTTs (including the initial
>> RTT required for the Cookie exchange).
>> When using DTLS/SCTP/UDP DTLS needs 2 RTTs (since there is no need for
>> the DTLS Cookie).
> 
> There's no need for the DTLS cookie in either case, actually, since ICE provides
> the appropriate proof of return routability.
I don't know much about ICE....
So assume that the endpoint willing to accept DTLS connections.
Can't I just send an ClientHello via plain UDP to the endpoint (assuming that I can reach it)?

Best regards
Michael
> 
> Also, DTLS should probably be used with False Start here, so you can reduce
> to one RTT.
> 
> -Ekr
>