[RTW] [dispatch] Does RTC-WEB need to pick a signaling protocol?

[Harald Alvestrand]

On 02/03/11 01:32, Justin Uberti wrote:
> I would expect that the APIs that this group creates would handle the 
> details of obtaining any needed addresses (whether they be local, 
> server reflexive, or relayed endpoints). Do we think there is a 
> significant security concern here (above and beyond exposing the 
> ability to send audio and video from your computer)?
Apart from the known security concerns that come automatically from 
sharing IP addresses (such as revealing your network attachment location 
to whoever gets the IP address), I don't see any huge ones.
>
> On Wed, Feb 2, 2011 at 7:49 PM, Bernard Aboba 
> <bernard_aboba at hotmail.com <mailto:bernard_aboba at hotmail.com>> wrote:
>
>     Alternatives can be explored for how to represent the information
>     provided by SDP, but the enumeration and testing of potential
>     endpoints within an offer-answer exchange is at the core of ICE
>     (RFC 5245), and is also a potential means for demonstrating media
>     authorization.  If the Javascript limitations on enumeration of
>     physical or logical addresses can't be overcome, we might have to
>     live with server reflexive and relayed endpoint identifiers
>     (assuming that server reflexive and relayed endpoint identifiers
>     don't trigger similar concerns).  Replacing addresses with names
>     could be done prior to the offer/answer exchange but this might
>     introduce vulnerabilities (e.g. voice hammer attacks based on DNS
>     cache poisoning).
>     ------------------------------------------------------------------------
>     Date: Wed, 2 Feb 2011 16:09:48 -0800
>     From: harald at alvestrand.no <mailto:harald at alvestrand.no>
>     To: rtc-web at alvestrand.no <mailto:rtc-web at alvestrand.no>
>     Subject: Re: [RTW] [dispatch] Does RTC-WEB need to pick a
>     signaling protocol?
>
>
>     On 02/02/11 11:19, Henry Sinnreich wrote:
>
>         Is there some understanding on the list on how the IP
>         addresses in SDP can be reconciled with the USAF RFC 3424?
>
>     Nit: UNSAF, not USAF.
>
>         http://www.rfc-editor.org/rfc/rfc3424.txt
>
>         “...a process whereby some
>            originating process attempts to determine or fix the
>         address (and
>            port) by which it is known - e.g. to be able to use address
>         data in
>            the protocol exchange, or to advertise a public address
>         from which it
>            will receive connections.
>         There are only heuristics and workarounds to attempt to
>         achieve this
>            effect; there is no 100% solution.  Since NATs may also
>         dynamically
>            reclaim or readjust translations, "keep-alive" and periodic re-
>            polling may be required.  Use of these workarounds MUST be
>         considered
>            transitional in IETF protocols, and a better architectural
>         solution
>            is being sought.  The explicit intention is to deprecate
>         any such
>            workarounds when sound technical approaches are available.”
>
>     In our case, the answer that has proved workable is called STUN.
>
>
>         Obviously there is much more dead stuff in SDP besides using
>         the misleading IP addresses, but this seems to be a deep
>         architectural flaw.
>         There were some early attempts to do SDPng and we know today
>         much more:
>         http://tools.ietf.org/html/draft-ietf-mmusic-sdpng-07
>
>         Why not replace SDP, since it deals only with a/v codec
>         negotiation with a more general, standards based metadata
>         approach?
>         For example including Web conferencing displays and UI control
>         capabilities.
>         Of course such a new approach must be easily mapped to the
>         existing global SIP VoIP infrastructure.
>
>         Or are the no  “sound technical approaches” available at all?
>
>     I'm all in favour of replacing SDP, but would not like to require
>     that before we can produce any output from this group.
>
>     Justin's idea of sorting out what information we need and
>     specifying how that maps into SDP (just like is currently done by
>     Jingle) might be a reasonable approach that can allow us to not
>     fossilize SDP's misfeatures forever.
>
>                            Harald
>
>
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>

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