Re: [tram] ALPN identifiers for STUN and TURN - what is an application?

[Paul Kyzivat <[e-mail]>]

On 7/31/14 2:26 PM, Martin Thomson wrote:
> On 31 July 2014 10:57, Prashanth Patil (praspati) <[e-mail]> wrote:
>> There was some discussion on the need for separate STUN and TURN identifiers
>> during the TRAM session. Separate identifiers could be useful when middle
>> boxes such as a firewall want protocol identification e.g as described in
>> http://tools.ietf.org/html/draft-hutton-httpbis-connect-protocol-00#section-1.
>
> I raised this concern previously, and it has been bothering me
> somewhat.  I'll try to make this a little clearer, and apologies for
> the rambling post.
>
> The application that you are using is what matters in this context.
> That's why we have ALPN identifiers for WebRTC.
>
> Identifying as TURN or STUN isn't as useful, particularly when it
> comes to enforcing policy, because they are effectively blank cheques.
> "You are establishing a tunnel to a relay, great, what for?"

I'll also argue that WebRTC is not an application.
It too is just a tunnel (or, if you preferr, transport).

Applications ride on top of it. I guess Meetecho or Webex++ or Skype++ 
would be plausible applications.

Of course this is a constantly changing game. We keep adding layers to 
the stack, and each time we do what used to be an application becomes 
just a transport for the next layer.

But AFAIK WebRTC is *never* an application in its own right.

ISTM that it would be more appropriate if the application identifier 
identified the complete protocol stack that is riding on top of the 
layer that is carrying the identifier.

	Thanks,
	Paul