Re: [tram] New Version Notification for draft-patil-tram-turn-serv-disc-01.txt

["Prashanth Patil (praspati)" <[e-mail]>]

Hi Karl,

On 5/18/14 6:13 PM, "Karl Stahl" <[e-mail]> wrote:

>I browsed through this document and to me it looks mature enough to be
>pushed forward (hopefully soon) to get an IANA anycast address etc., so
>these things can be put into current WebRTC browsers. As we know, many
>enterprises cannot use WebRTC at all today due to their restrictive
>firewall policies - they need a TURN server on their LAN, discovered
>and used by the WebRTC browsers to even begin using WebRTC.
>
>However, I raised a few questions and some suggestions
>http://www.ietf.org/mail-archive/web/tram/current/msg00480.html
>at the end of the previous version of this draft that never became
>discussed and remain:
>
>A) Under 8.2 there is a suggested way to assure that the TURN server
>returned by the anycast method, is provided by the network
>provider (and not some far away TURN server that should not be trusted
>to use without authentication): "... can set an IP TTL on their TURN
>requests that limits how far they can travel into the public Internet."
>
>I suggest that this TTL limitation is specified (e.g. Don't look further
>than 3 steps - local firewall + max 2 ISP routers) and brought into
>section "5. Discovery using Anycast" of the draft.

I think the decision should be left up to the application. We could,
maybe, make a recommendation at best (i.e. it is not a MUST).


>
>B) Shall we really have more than one method? If the Anycast method can
>be used by everyone, why then also have DHCP and now a two more methods?

There are essentially 2 methods described in the draft (1) Service
resolution and (2) Anycast. We'll probably need both if we want to
maximize chances of discovery.
DHCP happens to be one method to obtain the domain-name for (1) Service
resolution. While the DHCP method may not workable in some cases, the
other two methods (one of them inspired by draft-kist-alto-3pdisc) could
offer better results. We can do away with DHCP,  if that is the WG
consensus.


>
>I assume you intend that all webrtc browsers implement and can use all
>methods? Or? (If a service provider e.g. deploys DHCP discovered TURN
>servers, but some webrtc browser in some operating system don't
>find/cannot use the TURN server, it would be bad.)
>
>In previous discussions, there were some fears that DHCP options are
>not available in some common OSs. If so, I think the DHCP method should
>be skipped. 
>
>Also, if the other methods (other than anycast) may fail, why have them?

Anycast may fail, too.


> 
>Are they better to deploy and provision for network service providers?
>
>And will webrtc browsers implement all these methods?
>
>Do we have input/feedback on these questions?
>
>Should the "connect speed factor" not also be considered? Even though
>the auto discovery can be done in advance of a call, we should consider
>the mobility use case. With a mobile client changing network,
>LAN/LTE/public WiFi etc., we want to get up and run as soon as possible,
>so the auto discovery of a new TURN server should not be a tedious process
>
>And should the quick anycast auto discovery not be the first to be
>tried/used (which it is not now in the draft)?

Given that there is a service resolution mechanism for TURN over DTLS
(http://tools.ietf.org/html/draft-ietf-tram-stun-dtls-02#page-6), it seems
useful to do service resolution before.

>
>C) I noticed that referenced I-D.ietf-geopriv-res-gw-lis-discovery
>is now RFC7216.

Thanks, will update.

-Prashanth


>
>/Karl
>
>
>-----Ursprungligt meddelande-----
>Från: tram [mailto:[e-mail]] För Prashanth Patil (praspati)
>Skickat: den 2 maj 2014 12:02
>Till: [e-mail]
>Ämne: [tram] FW: New Version Notification for
>draft-patil-tram-turn-serv-disc-01.txt
>
>A new revision of the TURN server discovery draft has been published.
>Notable updates :
>
>* 300 (Try Alternate) response for anycast.
>* Mechanism described in draft-kist-alto-3pdisc i.e. using the clients own
>address to populate the DNS reverse zone (i.e., in-addr.arpa or ip6.arpa)
>with appropriate NAPTR records pointing to the TURN server.
>* Learning domain names from own identity.
>
>-Prashanth
>
>
>On 5/2/14 3:25 PM, "[e-mail]" <[e-mail]>
>wrote:
>
>>
>>A new version of I-D, draft-patil-tram-turn-serv-disc-01.txt
>>has been successfully submitted by Prashanth Patil and posted to the
>>IETF repository.
>>
>>Name:		draft-patil-tram-turn-serv-disc
>>Revision:	01
>>Title:		TURN Server Auto Discovery
>>Document date:	2014-05-02
>>Group:		Individual Submission
>>Pages:		11
>>URL:            
>>http://www.ietf.org/internet-drafts/draft-patil-tram-turn-serv-disc-01.tx
>>t
>>Status:         
>>https://datatracker.ietf.org/doc/draft-patil-tram-turn-serv-disc/
>>Htmlized:       
>>http://tools.ietf.org/html/draft-patil-tram-turn-serv-disc-01
>>Diff:           
>>http://www.ietf.org/rfcdiff?url2=draft-patil-tram-turn-serv-disc-01
>>
>>Abstract:
>>   Current Traversal Using Relays around NAT (TURN) server discovery
>>   mechanisms are relatively static and limited to explicit
>>   configuration.  These are usually under the administrative control of
>>   the application or TURN service provider, and not the enterprise or
>>   the ISP, the network in which the client is located.  Enterprises and
>>   ISPs wishing to provide their own TURN servers need auto discovery
>>   mechanisms that a TURN client could use with no or minimal
>>   configuration.  This document describes two such mechanisms for TURN
>>   server discovery.
>>
>>                 
>>        
>>
>>
>>Please note that it may take a couple of minutes from the time of
>>submission until the htmlized version and diff are available at
>>tools.ietf.org.
>>
>>The IETF Secretariat
>>
>
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