Re: draft-ietf-simple-msrp-cema-05 WGLC comments - Section 7 (Ben)

On 5/15/12 5:12 AM, Christer Holmberg wrote:

>> I think the way this is being presented involves some
>> dog-wagging. It's not so much that the end user wants to
>> trust the middleboxes as much as it is an operator that won't
>> let calls complete if they don't anchor on a middlebox. This
>> is a fairly coercive definition of trust.
>
> I don't think you ever *want* to trust anyone.
>
> The user has to make a decision whether he thinks the benefits
> of using the service outweighs the associated risk. If the
> answer is yes, then he trusts the service provider.
>
> In some cases it is not possible to setup a call without inserting a
> Middlebox (e.g. IPv4 user to IPv6 user). One could try to determine when
> an end-to-end TCP connection can be established but that is often complex.

You say there is need to anchor the media, perhaps because of v4/v6 
conversion, and then there is a need for a middle box to manipulate the 
SDP to accomplish that, and then 4474 can't be used because of the SDP 
manipulation.

But this can be short circuited as long as the UA participates in the 
media anchoring. If TURN is used by the UA to establish the media 
anchor, then it can make the SDP correct, which then allows 4474 to be used.

	Thanks,
	Paul