Re: [tram] Chime in on attched redlined version-12 WAS: I-D Action: draft-ietf-tram-turn-server-discovery-12.txt

[Karl Stahl <[e-mail]>]

Tiru,

That does not make the version -12 text in the draft any clearer about 
what the draft's anycast method actually is. I am asking you the same 
question as I asked Simon before (and only he answered):

Does the draft assume: 

(A) a TURN server listening to TWO IP addresses (that are at different 
subnets) that can respond error 300 or make an allocation, distinguished 
by whether the request was received on its anycast address or 
its unicast address, OR

(B) we really have TWO TURN servers to play with (the one at the anycast 
address being configured to respond with the error 300, OR 

(C) the FIRST Allocate is responded to with error 300 and SUBSEQUENT
Allocates actually are making TURN allocations. 


We cannot have an RFC, not even being clear about the method specified.

/Karl


-----Ursprungligt meddelande-----
Från: Tirumaleswar Reddy (tireddy) [mailto:[e-mail]] 
Skickat: den 7 februari 2017 07:18
Till: Simon Perreault; Karl Stahl; 'Spencer Dawkins at IETF'
Kopia: [e-mail]
Ämne: RE: [tram] Chime in on attched redlined version-12 WAS: I-D Action:
draft-ietf-tram-turn-server-discovery-12.txt

> -----Original Message-----
> From: Simon Perreault [mailto:[e-mail]]
> Sent: Friday, February 3, 2017 7:13 PM
> To: Karl Stahl <[e-mail]>; 'Spencer Dawkins at IETF'
> <[e-mail]>
> Cc: [e-mail]; Tirumaleswar Reddy (tireddy) <[e-mail]>
> Subject: Re: [tram] Chime in on attched redlined version-12 WAS: I-D
Action:
> draft-ietf-tram-turn-server-discovery-12.txt
> 
> Karl,
> 
> There is no consensus in the working group behind this new anycast
> mechanism. Therefore it can not be added to the draft, and the mechanism
> defined in RFC 5766 remains.

Yup, https://tools.ietf.org/html/rfc7094#section-3.4 also discusses similar
mechanism.
I don't see the need for a new anycast mechanism.

-Tiru

> 
> Thanks,
> Simon
> 
> Le 2017-02-02 à 18:23, Karl Stahl a écrit :
> > The -12 version of the draft does not include major remedies of flaws
> > that were un-addressed long before the DISCUSS, nor the latest
> > regarding the possible use of (D)TLS for auto discovered turn servers
> > provided the local or access network administrator, see
> >
> > https://www.ietf.org/mail-archive/web/tram/current/msg02216.html
> >
> >
> >
> > For the latest discussed, see
> >
> >
> >
> > https://www.ietf.org/mail-archive/web/tram/current/msg02279.html
> >
> >>> However, I think we need agreement on the justification for such a
> >
> >> change.
> >
> >> [Karl] Justification is in the (A), (B), (C) and (D) of
> >
> >> https://www.ietf.org/mail-archive/web/tram/current/msg02254.html
> >
> >> where saying Binding instead Allocate, is necessary to achieve (A)
> >> and
> > (B), and improves (C) and (D).
> >
> >
> >
> > Brandon> It is true that you have provided a justification for the
change.
> >
> >
> >
> > https://www.ietf.org/mail-archive/web/tram/current/msg02296.html
> >
> > The (D)TLS mandating was Author's idea to throw into version -10
> > during the discuss and remains in this version -11, breaking the
> > consensus text since version -7.
> >
> >
> >
> > https://www.ietf.org/mail-archive/web/tram/current/msg02297.html
> >
> > STUN dummy authentication instead of (D)TLS as suggested by Oleg
> > Moskalenko
> >
> >
> >
> >
> >
> > I have inserted my (now edited and adopted to the latest) redlining,
> > removal of blue options etc. into the -12 draft text as attached, for
> > the author to copy from and paste.
> >
> >
> >
> > Without my red lining, current version -12 is in conflict with RFC7478
> > (Web Real-Time Communication Use Cases and Requirements)  and does
> not
> > meet the need of [I-D.ietf-rtcweb-return] (Recursively Encapsulated
> > TURN) (see under redlined 7.2)
> >
> > and it does not do what was set out in the Charter and "Milestone 3:
> > TURN server auto-discovery mechanism for enterprise and ISPs"
> >
> >
> >
> > Further, the authors have in version -12 (compared to from before
> > DISCUSS)  changed the text "  6.  Discovery using Anycast " to:
> >
> > https://tools.ietf.org/rfcdiff?url1=draft-ietf-tram-turn-server-discov
> > ery-09.txt&url2=draft-ietf-tram-turn-server-discovery-12.txt
> >
> > "IP anycast can also be used for TURN service discovery.  A packet
> >
> >    sent to an anycast address is delivered to the "topologically
> >
> >    nearest" network interface with the anycast address.  Using the
> > TURN
> >
> >    anycast address, the only two things that need to be deployed in
> > the
> >
> >    network for discovery are the two things that actually use TURN.
> >
> >
> >
> >    When a client requires TURN services, it sends a TURN allocate
> >
> >    request to the assigned anycast address.  A TURN anycast server
> >
> >    performs checks 1 to 7 discussed in Section 6.2 of [RFC5766].  If
> > all
> >
> >    checks pass, the TURN anycast server MUST respond with a 300 (Try
> >
> >    Alternate) error as described in Section 2.9 of [RFC5766]; The
> >
> >    response contains the TURN unicast address in the ALTERNATE-SERVER
> >
> >    attribute.  For subsequent communication with the TURN server, the
> >
> >    client uses the responding server's unicast address.  This has to
> > be
> >
> >    done because two packets addressed to an anycast address may reach
> >
> >    two different anycast servers.  The client, thus, also needs to
> >
> >    ensure that the initial request fits in a single packet.  An
> >
> >    implementation may choose to send out every new TURN Allocation
> >
> >    request to the anycast address to discover the closest and the most
> >
> >    optimal unicast address for the TURN server."
> >
> >
> >
> > The highlighted "A TURN anycast server"  isnothing known nor described
> > (in fact there would have to be TWO TURN servers, one deployed at the
> > anycast address and another TURN server deployed at the unicast
> > address, reacting differently to the Allocation request) for this to
> > work as clarified in WG discussions with Simon).
> >
> >
> >
> > The last sentence "An  implementation may choose to send out every new
> > TURN Allocation request to the anycast address to discover the closest
> > and the most optimal unicast address for the TURN server." violates
> > security and deployment considerations (see red lined considerations
> > in attached).
> >
> >
> >
> > Further, the authors have in version -12 (compared to from before
> > DISCUSS)  changed the text "7.2.  Recursively Encapsulated TURN " to:
> >
> > https://tools.ietf.org/rfcdiff?url1=draft-ietf-tram-turn-server-discov
> > ery-09.txt&url2=draft-ietf-tram-turn-server-discovery-12.txt
> >
> > "WebRTC endpoints SHOULD treat any TURN server discovered through
> the
> >
> >    mechanisms described in this specification as an enterprise/gateway
> >
> >    or access network server, in accordance with Recursively
> > Encapsulated
> >
> >    TURN [I-D.ietf-rtcweb-return]."
> >
> >
> >
> > The text is a contradiction, since the return draft deals with TURN
> > servers provided by the local or access network, not other TURN
> > servers discovered by this draft.
> >
> >
> >
> > *Current -12 draft cannot be considered to be an RFC!*
> >
> >
> >
> > I suggest the redline version of draft -12 attached is chimed into now
> > and quickly merged into a version -13, so we can avoid the "Conflict
> > Resolution and Appeals"process hinted about in
> >
> > https://www.ietf.org/mail-archive/web/tram/current/msg02202.html,
> > further delaying what is needed for Internet real-time communication
> > and especially for WebRTC.
> >
> >
> >
> > /Karl
> >
> >
> >
> > *Från:*tram [mailto:[e-mail]] *För *Spencer Dawkins at
> > IETF
> > *Skickat:* den 1 februari 2017 22:12
> > *Till:* Simon Perreault
> > *Kopia:* [e-mail] <mailto:[e-mail]>; Tirumaleswar Reddy
> > (tireddy)
> > *Ämne:* Re: [tram] I-D Action:
> > draft-ietf-tram-turn-server-discovery-12.txt
> >
> >
> >
> > Hi, Simon,
> >
> >
> >
> > On Thu, Feb 2, 2017 at 6:00 AM, Simon Perreault <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> > Le 2017-02-01 à 15:37, Spencer Dawkins at IETF a écrit :
> >> Dear TRAMsters,
> >>
> >> On Fri, Jan 13, 2017 at 12:59 PM, Tirumaleswar Reddy (tireddy)
> >> <[e-mail]
> >> <mailto:[e-mail]><mailto:[e-mail]
> > <mailto:[e-mail]>>> wrote:
> >>
> >>     This revision addresses comments from Brandon.
> >>
> >>     -Tiru
> >>
> >>
> >> How close are we to asking Terry to clear the (last remaining) DISCUSS?
> >
> > Thanks for the reminder.
> >
> > If my co-chair and the authors have no objection, I think we're ready.
> >
> >
> >
> > I'll give this 24 hours for people to chime in, but I do want to ping
> > Terry.
> >
> >
> >
> > It's a little-appreciated thing, but AD ballot positions go away when
> > ADs go away; this document has 12 yes/no objections now, and you need
> > 10 for approval, and three are from ADs who are stepping down in March
> > ;-)
> >
> >
> >
> > Spencer
> >
> >
> >
> > _______________________________________________
> > tram mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/tram
> >
> 
> 
> --
> Simon Perreault
> Director of Engineering, Platform | Jive Communications, Inc.
> https://jive.com | [phone] ext. 1241 | [e-mail]