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

[Justin Uberti]

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)?

On Wed, Feb 2, 2011 at 7:49 PM, Bernard Aboba <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
> To: 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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