Re: [straw] Alissa Cooper's Discuss on draft-ietf-straw-b2bua-dtls-srtp-09: (with DISCUSS and COMMENT)

["Ben Campbell" <[e-mail]>]

On 23 Mar 2016, at 3:15, Tirumaleswar Reddy (tireddy) wrote:

>> -----Original Message-----
>> From: Ben Campbell [mailto:[e-mail]]
>> Sent: Wednesday, March 23, 2016 11:14 AM
>> To: Tirumaleswar Reddy (tireddy)
>> Cc: Ram Mohan R (rmohanr); Alissa Cooper; [e-mail];
>> [e-mail]
>> Subject: Re: [straw] Alissa Cooper's Discuss on 
>> draft-ietf-straw-b2bua-dtls-
>> srtp-09: (with DISCUSS and COMMENT)
>>
>> On 22 Mar 2016, at 23:00, Tirumaleswar Reddy (tireddy) wrote:
>>
>>>> -----Original Message-----
>>>> From: straw [mailto:[e-mail]] On Behalf Of Ram Mohan 
>>>> R
>>>> (rmohanr)
>>>> Sent: Tuesday, March 22, 2016 10:46 AM
>>>> To: Ben Campbell
>>>> Cc: Alissa Cooper; [e-mail]; [e-mail]
>>>> Subject: Re: [straw] Alissa Cooper's Discuss on
>>>> draft-ietf-straw-b2bua-dtls-
>>>> srtp-09: (with DISCUSS and COMMENT)
>>>>
>>>> Hi Ben,
>>>>
>>>> -----Original Message-----
>>>> From: Ben Campbell <[e-mail]>
>>>> Date: Tuesday, 22 March 2016 at 12:08 AM
>>>> To: Cisco Employee <[e-mail]>
>>>> Cc: Alissa Cooper <[e-mail]>, "[e-mail]"
>>>> <[e-mail]>,
>>>> "[e-mail]" <[e-mail]>
>>>> Subject: Re: [straw] Alissa Cooper's Discuss on
>>>> draft-ietf-straw-b2bua-dtls-srtp-09: (with DISCUSS and COMMENT)
>>>>
>>>>>> NEW:
>>>>>> B2BUAs may be deployed for address hiding or media latching
>>>>>> [RFC7362], although TURN is more often used for this purpose and
>>>>>> media latching is not recommended due to its security properties.
>>>>>> Such B2BUAs are able to perform their functions without requiring
>>>>>> termination of DTLS-SRTP sessions i.e.
>>>>>> these B2BUAs need not act as DTLS proxy and decrypt the RTP
>>>>>> payload.
>>>>>
>>>>> I think the statement that TURN is more often used for media
>>>>> latching is at least somewhat aspirational. But I'm okay with that
>>>>> aspiration
>>>>> :-)
>>>>
>>>> :) Agree. There are more B2BUAs out there in field doing latching
>>>> than people using TURN.
>>>> But I think there is no harm in saying this way.
>>>
>>> How about the following text ?
>>> B2BUAs may be deployed for address hiding or media latching 
>>> [RFC7362],
>>> although endpoints can use ICE, only advertise the relayed candidate
>>> allocated by the TURN server for address privacy to the remote peer
>>> and avoid the security threats discussed in Section 5 of [RFC7362].
>>>
>>
>>   My preference is the language that Ram and Alissa came up with
>> (aspirational or otherwise.) Aspirational or not, I think we should 
>> make it
>> clear that the IETF does not recommend SBC media latching and prefers
>> TURN.
>
> Got it, but TURN has to be used with ICE.

Sure, but it's not the point of this draft to teach the details of how 
to use TURN.

> NEW:
> B2BUAs may be deployed for address hiding or media latching [RFC7362], 
> although TURN [RFC5766] with ICE [RFC5245] is recommended for this 
> purpose and media latching is not recommended due to its security 
> properties.

I am okay with either this wording or Ram's.