Re: [rtcweb] New Version Notification for draft-chenxin-behave-turn-websocket-00.txt

[Simon Pietro Romano <[e-mail]>]

I keep on thinking that the solution depicted in http://tools.ietf.org/id/draft-miniero-rtcweb-http-fallback-00.txt deserves attention.

Simon

Il giorno 20/mag/2013, alle ore 13:06, Hutton, Andrew ha scritto:

> Regarding the HTTP fallback and whether this could be adapted to be a TURN over HTTP based solution then I think the same comments that were made on the TURN over websockets apply. What are the benefits of creating a new transport for TURN over what we can do using HTTP Connect as described in http://tools.ietf.org/html/draft-hutton-rtcweb-nat-firewall-considerations-00.
> 
> Having said that I am really happy we are having this debate as we really need to find a solution here that the browser vendors will implement so I would really like to know which options they prefer.
> 
> I really hope we can get draft-hutton-rtcweb-nat-firewall-considerations adopted and use it to document whatever the working group agrees on being the right solution.
> 
> Regards
> Andy
> 
> 
>> -----Original Message-----
>> From: Lorenzo Miniero [mailto:[e-mail]]
>> Sent: 20 May 2013 10:15
>> To: Gustavo García
>> Cc: Hutton, Andrew; [e-mail]; [e-mail]
>> Subject: Re: [rtcweb] New Version Notification for draft-chenxin-
>> behave-turn-websocket-00.txt
>> 
>> Il giorno Sun, 19 May 2013 23:20:41 -0700
>> Gustavo García <[e-mail]> ha scritto:
>> 
>>> I agree that TURN over websockets doesn't solve much more scenarios
>>> than TURN/TLS.   If trying to fix HTTP Proxy traversal why not doing
>>> it over HTTP that aside of philosophical discussions would be the
>>> solution with better success rate?  Otherwise we will have to
>>> continue answering for another 10 years "why is this app not working
>>> if skype does".
>>> 
>>> Something like this draft sent some months ago but perhaps for TURN
>>> instead of direct connections:
>>> http://tools.ietf.org/id/draft-miniero-rtcweb-http-fallback-00.txt
>>> 
>> 
>> 
>> When I submitted that draft this summer, I had that exact purpose in
>> mind, that is taking care of corner edge cases like restrictive proxies
>> and the like. Of course it was not meant to be a solution, just a way
>> to foster discussion in that direction. In that discussion I also
>> mentioned some work we did about this in the past, which in part
>> apparently ended up in draft-hutton-rtcweb-nat-firewall-considerations:
>> 
>> http://www.ietf.org/mail-archive/web/rtcweb/current/msg05041.html
>> 
>> At the time most people in the ML thought it was either too useless,
>> too complex or even harmful, considering it could be considered as a
>> "sneaky" way to circumvent rules added by a network administrator, and
>> so unacceptable. Anyway, as I said back then, a solution like this
>> doesn't have to be sneaky, and it could very well be conceived in order
>> to be admin-friendly rather than have a parrot and a wooden leg.
>> 
>> Whether we actually need something like this or TURN-over-443 is enough
>> I don't know: I still think it may be useful to tackle scenarios where
>> everything else fails (the "skype works here" effect), so I'd be glad
>> to be of help in that direction if needed.
>> 
>> Lorenzo
>> 
>> 
>> 
>>> On 16/05/2013, at 01:28, Hutton, Andrew wrote:
>>> 
>>>> I agree with Bernard's comments regarding the impact of DPI but of
>>>> course such DPI devices do what they do and we can't and even don't
>>>> want to stop them from doing it. However for the case when policy
>>>> is such that the firewall will only allow traffic to traverse that
>>>> comes from the HTTP Proxy or a network specific TURN server and
>>>> there is no deliberate policy to block WebRTC media we need a
>>>> solution and this is what
>>>> draft-hutton-rtcweb-nat-firewall-considerations-00 addresses.
>>>> 
>>>> So far I don't see the benefit that TURN over websockets would have
>>>> in this scenario and it needs additional implementation in the
>>>> browser and the TURN server.
>>>> 
>>>> Regards
>>>> Andy
>>>> 
>>>> 
>>>>> -----Original Message-----
>>>>> From: Bernard Aboba [mailto:[e-mail]]
>>>>> Sent: 15 May 2013 18:20
>>>>> To: Hutton, Andrew; Chenxin (Xin); [e-mail];
>> [e-mail]
>>>>> Subject: RE: [rtcweb] FW: New Version Notification for
>>>>> draft-chenxin- behave-turn-websocket-00.txt
>>>>> 
>>>>> Andrew Hutton said:
>>>>>> When we wrote the draft http://tools.ietf.org/html/draft-hutton-
>>>>> rtcweb-nat-firewall-considerations-00 we did not include this
>>>>> option because we did not see the benefit of additional transport
>>>>> options for TURN given that the existing options (E.g. TURN/TCP
>>>>> and TURN/TLS) seem to be meet our needs.
>>>>>> 
>>>>>> So what would be the benefits that justify this addition
>> transport
>>>>> option for TURN?
>>>>> 
>>>>> [BA] In my experience,  institutions with very restrictive
>> security
>>>>> policies (e.g. those that don't allow UDP in or out) also tend to
>>>>> deploy other measures such as deep packet inspection.   So just
>>>>> because some traffic is allowed in or out on port 80 does not mean
>>>>> that TURN/TCP will be allowed on that port - a DPI box may examine
>>>>> the traffic and complain if it doesn't see HTTP being used.  On
>>>>> the other hand, unless the DPI box is upgraded, it will also
>>>>> complain about websockets.  So I think draft-chenxin only helps in
>>>>> a situation where TURN over Websockets would be allowed when
>>>>> TURN/TCP would not be.  That scenario is rare, at least at the
>>>>> moment.
>>>>> 
>>>>> The argument for TURN over Websocket/TLS is even more difficult to
>>>>> make. While DPI boxes may examine traffic destined to port 443
>>>>> carefully to make sure that TLS is really being used,  assuming
>>>>> that the DPI box does not see anything it considers fishy, the TLS
>>>>> exchange will complete and the DPI box will lose visibility.
>>>>> After TLS is running, the DPI box does not have much information
>>>>> available to distinguish TURN/TLS from HTTP over TLS, with or
>>>>> without websockets -- and those things it does have (such as
>>>>> packet size) are as likely to result in an objection to websocket
>>>>> transport as TURN/TLS.  So I'm not sure that draft-chenxin will
>>>>> help in that situation either.
>>>> 
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> rtcweb mailing list
>>>> [e-mail]
>>>> https://www.ietf.org/mailman/listinfo/rtcweb
>>> 
>>> _______________________________________________
>>> rtcweb mailing list
>>> [e-mail]
>>> https://www.ietf.org/mailman/listinfo/rtcweb
> 
> _______________________________________________
> rtcweb mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/rtcweb

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                    				Simon Pietro Romano
             				 Universita' di Napoli Federico II
                		     Computer Engineering Department 
	             Phone: [phone] -- Fax: [phone]
                                           e-mail: [e-mail]

		    <<Molti mi dicono che lo scoraggiamento Ë l'alibi degli 
		    idioti. Ci rifletto un istante; e mi scoraggio>>. Magritte.
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