Re: Allowing RTCIceServer to contain multiple URLs

On Thu, Jun 6, 2013 at 9:42 PM, Cullen Jennings (fluffy)
<fluffy@cisco.com>wrote:

>
> On Jun 6, 2013, at 10:30 PM, Justin Uberti <juberti@google.com> wrote:
>
> > The sections you are pointing to discuss the use of SRV to perform a
> lookup of a STUN or TURN server for a particular domain. How did you see
> this working with a TURN URI?
> >
> > That is, if the TURN URI specifies turn:foo.example.com, are you
> expecting the browser to do a SRV lookup of _turn._udp.foo.example.com,
> _turn._tcp.foo.example.com, and _turns._tcp.foo.example.com - each of
> which will return a DNS name that will require another query to obtain the
> IP address?
> >
> >
>
> Yes. Pretty much. Keep in mind the server has no idea which will works so
> you are going to need to try the transports to see what works.
>
> A TURN client could lookup the UDP, start trying that  and in parallel go
> get DNS for tcp and test the TCP. If UPD (or TCP) does not work, it takes
> awhile to detect so parallel works out better.
>

Do we have measurements on the SRV success rate from typical browser
clients?



> Related to this - for a web scale deployment, I'd do it much like google
> does DNS and have all the TURN servers have the same IP address so it can
> be cached for a long time then use any cast to get to the geographically
> close TURN server.
>

Hmm... Anycast really isn't guaranteed to be stable over this kind of time
scale.

-Ekr