Subject: Re: [bfcpbis] draft-ietf-bfcpbis-rfc4583bis

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Mon, 21 Sep 2015 17:53:37 +0000

RFC 5763, which is currently required for BFCP with DTLS reads:

   o  The endpoint MUST NOT use the connection attribute defined in
     [RFC4145 <https://tools.ietf.org/html/rfc4145>].

Section 5.1 of draft-ietf-mmusic-dtls-sdp reads:

   When used with DTLS, there is no default value defined for the
   attribute.  Implementations that wish to use the attribute MUST
   explicitly include it in SDP offers and answers.  If an offer or
   answer does not contain an attribute, other means needs to be used in
   order for endpoints to determine whether an offer or answer is
   associated with an event that requires the DTLS association to be re-
   established.

I suppose if draft-ietf-mmusic-dtls-sdp pulls in enough from RFC 5763 to
make it clear how the DTLS establishment and re-establishment works for
the case of which the connection attribute is not used, then we can change
the reference from RFC 5763 to draft-ietf-mmusic-dtls-sdp.

The last several updates of draft-ietf-bfcpbis-rfc4583bis have removed
supporting text from the draft in favor of pointing to RFC 5763 as the
source of truth. I fear that draft-ietf-mmusic-dtls-sdp in its current
state does not serve that need for draft-ietf-bfcpbis-rfc4583bis. I value
Christer’s thoughts and welcome the opinion of others, especially those
who have or are implementing BFCP with DTLS and ICE, which I have not.

Cheers,
Charles

On 9/21/15, 9:32 AM, "bfcpbis on behalf of Christer Holmberg"
<[email-masked] on behalf of [email-masked]>
wrote:

>Hi Charles,
>
>>The problem I see with this is that it is not just a matter of changing
>>the reference, it is also a matter of changing the normative behavior.
>>For DTLS with BFCP, we never required the use of the >“connection”
>>attribute.
>>If we are to start requiring it, we would need add text to describe how
>>to address backward compatibility in cases in which the connection
>>attribute is not specified.
>
>The intention is to cover backward compatibility in the draft.
>
>>Are there plans for this within RFC 5763bis draft? If so, Tom’s
>>recommendation of continuing to point to RFC 5763 for now may be the
>>best approach.
>
>I am not familiar with the 5763bis draft. But, even if the DTLS-SDP draft
>makes updates to 5763, it won't become a 5763bis draft.
>
>Regards,
>
>Christer
> 
>
>
>On 9/11/15, 1:11 PM, "Christer Holmberg" <[email-masked]>
>wrote:
>
>>Hi,
>>
>>>Hmm, yes maybe an idea if it's fine proceeding with referring a
>>>work-in-progress draft here.
>>>What if we keep the text and adds this as an additional reference in
>>>the two new text passages proposed by Charles: "... [13], and the
>>>clarifications defined in [draft-ietf-mmusic-dtls-sdp], ...".
>>>
>>>Where [13] is a reference to RFC 5763.
>>
>>My suggestion is to *only* refer the new dtls-sdp draft. Because, one
>>of the ideas with the new draft is to also update RFC 5763 to reference
>>the new dtls-sdp draft.
>>
>>>Anyway, I'd still prefer to keep the text in
>>>draft-ietf-bfcpbis-rfc4583bis-12 and redirect the readers to the
>>>rfc5763bis, that eventually then will obsolete (or extend?) RFC 5763.
>>
>>The new dtls-sdp draft will not become 5763bis (eventhough it MAY
>>update some parts of 5763). It's a generic document, which *any* DTLS
>>usage can then reference.
>>
>>Regards,
>>
>>Christer
>>
>>
>>
>>On 09/11/2015 01:25 PM, Christer Holmberg wrote:
>>> Hi,
>>>
>>> My suggestion would actually be to refer to the new
>>>draft-ietf-mmusic-dtls-sdp, which is going to clarify the DTLS-SRTP
>>>rules regarding when a new DTLS association must be established.
>>>
>>> Regards,
>>>
>>> Christer
>>>
>>> -----Original Message-----
>>> From: Tom Kristensen [mailto:[email-masked]]
>>> Sent: 11. syyskuuta 2015 13:25
>>> To: Charles Eckel (eckelcu)
>>> Cc: Christer Holmberg; Alissa Cooper; Gonzalo Camarillo;
>>> [email-masked]; Ben Campbell;
>>> [email-masked]
>>> Subject: Re: draft-ietf-bfcpbis-rfc4583bis
>>>
>>> Pointing to the DTLS-SRTP (and by that any updates of it) is a
>>>simple, safe and straigt-forward solution.
>>>
>>> The only change in the new version of rfc4583bis just submitted. And
>>>as Charles says, this should be the last missing fix for this draft
>>>until next stages in the process at least.
>>>
>>> -- Tom
>>>
>>> On 09/08/2015 07:48 PM, Charles Eckel (eckelcu) wrote:
>>>    
>>>> Picking up on this old thread regarding draft-ietf-bfcpbis-rfc4583bis.
>>>> I think this is the only outstanding item with respect to the
>>>>current  version of the draft. Unless anyone has an issue with the
>>>>proposed  resolution, I request we update the draft accordingly and
>>>>then use it  as the basis for Mary, the document shepherd, to provide
>>>>a proto writeup.
>>>>
>>>> Cheers,
>>>> Charles
>>>>
>>>>
>>>> On 4/20/15, 10:39 AM, "Charles Eckel (eckelcu)"<[email-masked]>
>>>>wrote:
>>>>
>>>>
>>>>      
>>>>> Hi Christer,
>>>>>
>>>>> I reread the current draft and went through the following MMUSIC
>>>>> thread on this subject:
>>>>> http://www.ietf.org/mail-archive/web/mmusic/current/msg14631.html
>>>>>
>>>>> As a result, I better understand the issue you are addressing. I
>>>>> suggest the following changes to be consistent with what is being
>>>>> proposed in
>>>>> MMUSIC:
>>>>>
>>>>> ------------
>>>>> Section 9:
>>>>>
>>>>> OLD:
>>>>> Endpoints that use the offer/answer model to establish a DTLS
>>>>>     association MUST support the 'setup' attribute, as defined in
>>>>>[7].
>>>>> When DTLS is used with UDP, the 'setup' attribute indicates which
>>>>> of the endpoints (client or floor control server) initiates the
>>>>> DTLS association setup. The requirements for the offer/answer
>>>>> exchange specified in [13], Section 5 of [13] MUST be followed when
>>>>>using DTLS.
>>>>> Offer/answer considerations are described in Section 10.5.
>>>>>
>>>>> NEW:
>>>>> When DTLS is used with UDP, the requirements specified in Section 5
>>>>> of [13] MUST be followed.
>>>>>
>>>>>
>>>>> Section 10.5
>>>>>
>>>>> OLD
>>>>>     If the transport parameters or the key fingerprints change, the
>>>>>     endpoints MUST establish a new DTLS connection.  In such case the
>>>>>     'active/passive' status of the endpoints will again be determined
>>>>>     following the procedures in [7], and the new status will be
>>>>>used to
>>>>>     determine the TLS roles associated with the new DTLS connection.
>>>>>
>>>>>        Informational note: The procedure above is identical to the
>>>>>one
>>>>>        defined for DTLS-SRTP in [13].
>>>>>
>>>>>        Note: A new DTLS connection needs to be established if the
>>>>>        transport parameters or the key fingerprints change.
>>>>>
>>>>>
>>>>>
>>>>> NEW:
>>>>> The conditions under which endpoints MUST establish a new DTLS
>>>>> connection are as the same defined for DTLS-SRTP in [13].
>>>>> ————————
>>>>>
>>>>> This way we avoid any potential conflicts with the intent of RFC
>>>>> 5763, and when clarifications to RFC 5763 are made, they will be
>>>>> picked up by the BFCP spec.
>>>>>
>>>>> Cheers,
>>>>> Charles
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 4/18/15, 2:01 PM, "Christer
>>>>> Holmberg"<[email-masked]>
>>>>> wrote:
>>>>>
>>>>>
>>>>>        
>>>>>> Hi Charles,
>>>>>>
>>>>>>
>>>>>>          
>>>>>>> [adding bfcppbis list]
>>>>>>>
>>>>>>> Hi Christer,
>>>>>>>
>>>>>>> Thanks for your review and comments. In the BFCP usage, the DTLS
>>>>>>> connection is dedicated to the BFCP stream it contains. As I
>>>>>>> understand it, the complications around DTLS re-establishement
>>>>>>> discussed in MMUSIC result from use of a single DTLS connection
>>>>>>> for multiple RTP and/or SCTP streams. Those complications do not
>>>>>>> exist with the BFCP usage, so I think it is sufficient to
>>>>>>> continue to reference RFC 5763 and not use the SDP connection
>>>>>>>attribute.
>>>>>>>
>>>>>>>            
>>>>>> The complications do not result from use of a single DTLS
>>>>>> connection for multiple streams - it mainly results from the usage
>>>>>> of ICE. And, as far as I know, ICE can be used also for BFCP.
>>>>>>
>>>>>> And, even without ICE we intend to add text saying that a DTLS
>>>>>>connection is only re-established if the underlying transport
>>>>>>changes.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Christer
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>          
>>>>>>> Hi,
>>>>>>>
>>>>>>> First, I want to apologize for not providing my review earlier.
>>>>>>>
>>>>>>> As far as the BFCP specifics are concerned, I am ok with the
>>>>>>> latest version of the draft.
>>>>>>>
>>>>>>> However, there is an issue regarding the DTLS considerations
>>>>>>> (section 10.5).
>>>>>>>
>>>>>>> The text says:
>>>>>>>
>>>>>>> 	"Once a DTLS connection has been established, if the
>>>>>>>'active/passive'
>>>>>>>     	status of the endpoints change during a session, a new DTLS
>>>>>>>     	connection MUST be established."
>>>>>>>
>>>>>>> There is currently an ongoing discussion in MMUSIC about when a
>>>>>>> DTLS connection is to be re-established.
>>>>>>>
>>>>>>> The discussion is still ongoing, but the outcome will most likely
>>>>>>> NOT be aligned with the text above.
>>>>>>>
>>>>>>> For example, there has been a suggestion (by myself) to use the
>>>>>>> SDP connection attribute to explicitly indicate that a new DTLS
>>>>>>> connection needs to be established.
>>>>>>>
>>>>>>>
>>>>>>> The draft also says:
>>>>>>>
>>>>>>> 	"If the transport parameters or the key fingerprints change, the
>>>>>>>     	endpoints MUST establish a new DTLS connection."
>>>>>>>
>>>>>>> This is related to the earlier issue. There is the discussion
>>>>>>> about ICE "virtual connections", and that a single DTLS
>>>>>>> connection would apply to all ICE candidates associated with an
>>>>>>> m- line. So, even if a candidate changes (read: transport
>>>>>>> parameter changes), it would not automatically trigger a new DTLS
>>>>>>>connection.
>>>>>>>
>>>>>>>
>>>>>>> The issues above are also holding up the SCTP-SDP draft, so it
>>>>>>> doesn't only affect BFCPbis :)
>>>>>>>
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>> Christer
>>>>>>>
>>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Alissa Cooper [mailto:[email-masked]]
>>>>>>> Sent: 8. huhtikuuta 2015 3:07
>>>>>>> To: Charles Eckel (eckelcu)
>>>>>>> Cc: Gonzalo Camarillo; Tom Kristensen (tomkrist);
>>>>>>> [email-masked]; Ben Campbell;
>>>>>>> Christer Holmberg
>>>>>>> Subject: Re: draft-ietf-bfcpbis-rfc4583bis
>>>>>>>
>>>>>>> Adding Christer to this thread.
>>>>>>>
>>>>>>> On Apr 7, 2015, at 12:44 PM, Charles Eckel (eckelcu)
>>>>>>> <[email-masked]>
>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>            
>>>>>>>> Christer (cc’d) and I discussed some of the changes offlist in
>>>>>>>> Dallas, and he is to come back to the list with comments after
>>>>>>>> Dallas
>>>>>>>> - which is now :)
>>>>>>>>
>>>>>>>> Cheers,
>>>>>>>> Charles
>>>>>>>>
>>>>>>>> On 4/7/15, 10:26 AM, "Alissa Cooper"<[email-masked]>   wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>           
>>>>>>>>> Checking in on this — has Christer been prompted to review the
>>>>>>>>> latest rev of draft-ietf-bfcpbis-rfc4583bis?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Alissa
>>>>>>>>>
>>>>>>>>> On Feb 25, 2015, at 9:14 AM, Charles Eckel (eckelcu)
>>>>>>>>> <[email-masked]>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>          
>>>>>>>>>> Most of the changes I this recent update to rfc4583bis were
>>>>>>>>>> inspired by comments and suggested text provided by Christer.
>>>>>>>>>> He is in the process of reviewing. If all goes well with that,
>>>>>>>>>> we are ready to proceed with proto writeup (Mary) and AD review.
>>>>>>>>>>
>>>>>>>>>> Cheers,
>>>>>>>>>> Charles
>>>>>>>>>>
>>>>>>>>>> On 2/25/15, 7:01 AM, "Alissa Cooper"<[email-masked]>   wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>         
>>>>>>>>>>> rfc4583 has not had an AD review yet. Richard can hopefully
>>>>>>>>>>> take care of that while I¹m on leave (starting today,
>>>>>>>>>>>actually).
>>>>>>>>>>>
>>>>>>>>>>> On Feb 25, 2015, at 2:56 AM, Gonzalo Camarillo
>>>>>>>>>>> <[email-masked]>   wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>        
>>>>>>>>>>>> Hi Alissa,
>>>>>>>>>>>>
>>>>>>>>>>>> I have noted that while rfc4582bis in on the agenda of the
>>>>>>>>>>>> March 5th telechat (thanks for handling that!), rfc4583bis
>>>>>>>>>>>> isn't. Tom revised rfc4583bis on February 20th. Should
>>>>>>>>>>>> rfc4583bis be on the agenda of the telechat as well or there
>>>>>>>>>>>> is still something left for Tom to take care of?
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>
>>>>>>>>>>>> Gonzalo
>>>>>>>>>>>>
>>>>>>>>>>>> On 18/02/2015 9:28 PM, Alissa Cooper wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>       
>>>>>>>>>>>>> Pinging on this.
>>>>>>>>>>>>>
>>>>>>>>>>>>> March 5 will likely be my last telechat before going on
>>>>>>>>>>>>> leave, so  it would be great to get this scheduled on that
>>>>>>>>>>>>> one. To do that,  the rev needs to be posted today. The
>>>>>>>>>>>>> updates are pretty minimal  and are all basically written
>>>>>>>>>>>>> up in Charles¹ response to my AD review.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Feb 15, 2015, at 9:13 AM, Gonzalo Camarillo
>>>>>>>>>>>>> <[email-masked]
>>>>>>>>>>>>> <mailto:[email-masked]>>
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>>      
>>>>>>>>>>>>>> I have talked offline with the other authors and Tom is
>>>>>>>>>>>>>>holding the pen. Tom, do you think you can meet the time
>>>>>>>>>>>>>>frame below?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Gonzalo
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Sent from my mobile
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> ---- Alissa Cooper wrote ----
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Just wanted to see if this rev might get done in the next
>>>>>>>>>>>>>> couple  of days. If so, we could get it on the next
>>>>>>>>>>>>>> telechat agenda (March 5).
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Begin forwarded message:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>     
>>>>>>>>>>>>>>> *From: *Alissa Cooper<[email-masked]
>>>>>>>>>>>>>>> <mailto:[email-masked]>>
>>>>>>>>>>>>>>> *Subject: **Re: [bfcpbis] AD evaluation:
>>>>>>>>>>>>>>> draft-ietf-bfcpbis-rfc4582bis-12*
>>>>>>>>>>>>>>> *Date: *February 9, 2015 at 3:58:52 PM PST
>>>>>>>>>>>>>>> *To: *"Charles Eckel (eckelcu)"<[email-masked]
>>>>>>>>>>>>>>> <mailto:[email-masked]>>
>>>>>>>>>>>>>>> *Cc: *"[email-masked]<mailto:[email-masked]>"
>>>>>>>>>>>>>>> <[email-masked]
>>>>>>>>>>>>>>> <mailto:[email-masked]>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Hi Charles,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks, some responses inline.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Feb 4, 2015, at 10:40 AM, Charles Eckel (eckelcu)
>>>>>>>>>>>>>>> <[email-masked]<mailto:[email-masked]>>   wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>>> HI Alissa,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you for the review. Please see my thoughts on your
>>>>>>>>>>>>>>>> comments and questions inline.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> From: Alissa Cooper<[email-masked]
>>>>>>>>>>>>>>>> <mailto:[email-masked]>>
>>>>>>>>>>>>>>>> Date: Thursday, January 29, 2015 at 10:19 PM
>>>>>>>>>>>>>>>> To: "[email-masked]<mailto:[email-masked]>"
>>>>>>>>>>>>>>>> <[email-masked]<mailto:[email-masked]>>
>>>>>>>>>>>>>>>> Subject: [bfcpbis] AD evaluation:
>>>>>>>>>>>>>>>> draft-ietf-bfcpbis-rfc4582bis-12
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>> I have reviewed this draft in preparation for IETF LC.
>>>>>>>>>>>>>>>>> Overall the document appears in good shape. I have a
>>>>>>>>>>>>>>>>> few questions and comments I¹d like to discuss before
>>>>>>>>>>>>>>>>> issuing the IETF last call. I¹ve also included some
>>>>>>>>>>>>>>>>> editorial nits that should be addressed together with
>>>>>>>>>>>>>>>>> any last call comments.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Comments and questions:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section 5.1 =
>>>>>>>>>>>>>>>>> "If an endpoint receives a message with an  unsupported
>>>>>>>>>>>>>>>>> version field value, the receiving server MUST send an
>>>>>>>>>>>>>>>>> Error message with parameter value 12 (Unsupported
>>>>>>>>>>>>>>>>> Version) to indicate this.²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> This seems a little misleading since RFC 4582 didn¹t
>>>>>>>>>>>>>>>>> specify what to do upon receipt of a message with a
>>>>>>>>>>>>>>>>> version other than 1.
>>>>>>>>>>>>>>>>> Implementations that do not get upgraded to be
>>>>>>>>>>>>>>>>> compliant with  4582bis (which could certainly account
>>>>>>>>>>>>>>>>> for some of those that  will not support version 2)
>>>>>>>>>>>>>>>>> will therefore never send the  error specified here.
>>>>>>>>>>>>>>>>> This seems like it should at least be  noted given the
>>>>>>>>>>>>>>>>> MUST-level requirement. The same applies in  Section
>>>>>>>>>>>>>>>>>13.7.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Good point. I believe we made this a MUST because we
>>>>>>>>>>>>>>>> were thinking in terms of implementations compliant with
>>>>>>>>>>>>>>>> this bis version.
>>>>>>>>>>>>>>>> Adding
>>>>>>>>>>>>>>>> your suggested note about rfc 4582 implementations here
>>>>>>>>>>>>>>>> and in  section 13.7 seems useful to me.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> Ok
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>> = Section 7 =
>>>>>>>>>>>>>>>>> "BFCP entities MUST support, at a minimum, the
>>>>>>>>>>>>>>>>> TLS_RSA_WITH_AES_128_CBC_SHA ciphersuite [6].²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I realize this requirement comes from RFC 4582, but I¹d
>>>>>>>>>>>>>>>>> like to understand why it has not been updated to be
>>>>>>>>>>>>>>>>> consistent with more current guidance on cipher suite
>>>>>>>>>>>>>>>>> selection (e.g.,
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> https://tools.ietf.org/html/draft-ietf-uta-tls-bcp-08#s
>>>>>>>>>>>>>>>>> e
>>>>>>>>>>>>>>>>> c
>>>>>>>>>>>>>>>>> tion
>>>>>>>>>>>>>>>>> -4)
>>>>>>>>>>>>>>>>> .
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> How about we keep this minimum requirement, and add a
>>>>>>>>>>>>>>>> reference to draft-ietf-uta-tls-bcp along with a
>>>>>>>>>>>>>>>> recommendation to adhere to the best practices it
>>>>>>>>>>>>>>>> outlines in section 4?
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> I think MUST support TLS_RSA_WITH_AES_128_CBC_SHA for
>>>>>>>>>>>>>>> backwards compatibility and SHOULD support the ones
>>>>>>>>>>>>>>> listed in the UTA drafts would be ok.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>> = Sections 8, 8.1, 8.2 = It seems like the transaction
>>>>>>>>>>>>>>>>> ID requirements regarding non-reuse/monotonically
>>>>>>>>>>>>>>>>> increasing IDs are re-stated multiple times across
>>>>>>>>>>>>>>>>> these three sections, in slightly different ways, to
>>>>>>>>>>>>>>>>> the point where it¹s not clear exactly what they are.
>>>>>>>>>>>>>>>>> It seems like they are:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> (1) Reliable transport, server-initiated transaction:
>>>>>>>>>>>>>>>>> ID is
>>>>>>>>>>>>>>>>> 0
>>>>>>>>>>>>>>>>> (2) Unreliable transport, server-initiated transaction:
>>>>>>>>>>>>>>>>> ID MUST be monotonically increasing (except for
>>>>>>>>>>>>>>>>> wrap-around)
>>>>>>>>>>>>>>>>> (3) Reliable transport, client-initiated transaction:
>>>>>>>>>>>>>>>>> ID MUST NOT be 0 and MUST NOT be reused in another
>>>>>>>>>>>>>>>>> message from the client until a response from the
>>>>>>>>>>>>>>>>> server is received for the transaction, but need not be
>>>>>>>>>>>>>>>>> monotonically increasing (e.g., a lower, recently used
>>>>>>>>>>>>>>>>> ID could be re-used once a response is
>>>>>>>>>>>>>>>>> received)
>>>>>>>>>>>>>>>>> (4) Unreliable transport, client-initiated transaction:
>>>>>>>>>>>>>>>>> ID MUST be monotonically increasing (except for
>>>>>>>>>>>>>>>>> wrap-around)
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Is (3) the correct interpretation of the text in 8.1?
>>>>>>>>>>>>>>>>> If so, why not just require IDs in all client-initiated
>>>>>>>>>>>>>>>>> transactions to be monotonically increasing?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Agree we can and should simplify this. Sections 8.1 and
>>>>>>>>>>>>>>>> 8.2 cover the client behavior and server behavior in
>>>>>>>>>>>>>>>> detail. As such, the transaction ID related information
>>>>>>>>>>>>>>>> at the start of Section 8 is superfluous. I recommend
>>>>>>>>>>>>>>>> reducing the text in Section 8 to the
>>>>>>>>>>>>>>>> follow:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 8. Protocol Transactions
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> In BFCP, there are two types of transactions:
>>>>>>>>>>>>>>>> client-initiated transactions and server-initiated
>>>>>>>>>>>>>>>> transactions.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Client-initiated transactions consist of a request from
>>>>>>>>>>>>>>>> a client to a floor control server and a response from
>>>>>>>>>>>>>>>> the floor control server to the client.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Server-initiated transactions have different behavior
>>>>>>>>>>>>>>>> depending on underlying transport:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>      When using a reliable transport, server-initiated
>>>>>>>>>>>>>>>>transactions
>>>>>>>>>>>>>>>>      consist of a single message from a floor control
>>>>>>>>>>>>>>>>server to a
>>>>>>>>>>>>>>>>      client (notifications).  They do not trigger any
>>>>>>>>>>>>>>>>response.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>      When using an unreliable transport,
>>>>>>>>>>>>>>>> server-initiated transactions
>>>>>>>>>>>>>>>>      consist of a request from a floor control server to
>>>>>>>>>>>>>>>> a client and a
>>>>>>>>>>>>>>>>      response from the client to the floor control server.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> When using BFCP over an unreliable transport,
>>>>>>>>>>>>>>>> retransmission timer T1 (see Section 8.3) MUST be used
>>>>>>>>>>>>>>>> for all requests until the transaction is completed.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Then in section 8.1, we add the important details
>>>>>>>>>>>>>>>> removed from section 8.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 8.1.1 Client Behavior
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> A client starting a client-initiated transaction MUST
>>>>>>>>>>>>>>>> set the Conference ID in the common header of the
>>>>>>>>>>>>>>>> message to the Conference ID for the conference that the
>>>>>>>>>>>>>>>> client obtained previously.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> The client MUST set the Transaction ID value in the
>>>>>>>>>>>>>>>>common header to a number that is different from 0 and
>>>>>>>>>>>>>>>>that MUST NOT be reused in another message from the
>>>>>>>>>>>>>>>>client until a response from the server is received for
>>>>>>>>>>>>>>>>the transaction.
>>>>>>>>>>>>>>>> The client uses the Transaction ID value to match this
>>>>>>>>>>>>>>>>message with the response from the floor control server.
>>>>>>>>>>>>>>>> When using BFCP over an unreliable transport, it is
>>>>>>>>>>>>>>>>important to choose a Transaction ID value that lets the
>>>>>>>>>>>>>>>>receiver distinguish the reception of the next message in
>>>>>>>>>>>>>>>>a sequence of BFCP messages from a retransmission of a
>>>>>>>>>>>>>>>>previous message.  Therefore, BFCP entities using an
>>>>>>>>>>>>>>>>unreliable transport MUST use monotonically increasing
>>>>>>>>>>>>>>>>Transaction ID values (except for wrap-around).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> A client receiving a server-initiated transaction over
>>>>>>>>>>>>>>>> an unreliable transport MUST copy the Transaction ID
>>>>>>>>>>>>>>>> from the request received from the server into the
>>>>>>>>>>>>>>>>response.
>>>>>>>>>>>>>>>> [Question: is there a need to copy the Conference ID and
>>>>>>>>>>>>>>>> User ID, if present?]
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 8.2. Server Behavior
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> A floor control server sending a response within a
>>>>>>>>>>>>>>>> client-initiated transaction MUST copy the Conference
>>>>>>>>>>>>>>>> ID, the Transaction ID, and the User ID from the request
>>>>>>>>>>>>>>>> received from the client into the response.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Server-initiated transactions MUST contain a Transaction
>>>>>>>>>>>>>>>>ID equal to
>>>>>>>>>>>>>>>> 0 when BFCP is used over a reliable transport.  Over an
>>>>>>>>>>>>>>>>unreliable transport, the Transaction ID shall have the
>>>>>>>>>>>>>>>>same properties as for client-initiated transactions. The
>>>>>>>>>>>>>>>>server uses the Transaction ID value to match this
>>>>>>>>>>>>>>>>message with the response from the floor participant or
>>>>>>>>>>>>>>>>floor chair.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> Thanks, this is better.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>>>> = Section 9 (impacts Section 14 as well) = "BFCP
>>>>>>>>>>>>>>>>>clients  SHOULD authenticate the floor control server
>>>>>>>>>>>>>>>>>before  sending any BFCP message to it or accepting any
>>>>>>>>>>>>>>>>>BFCP message from it.
>>>>>>>>>>>>>>>>> Similarly, floor control servers SHOULD authenticate a
>>>>>>>>>>>>>>>>>client before accepting any BFCP message from it or
>>>>>>>>>>>>>>>>>sending any BFCP message to it.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> BFCP supports TLS/DTLS mutual authentication between
>>>>>>>>>>>>>>>>>clients and floor control servers, as specified in
>>>>>>>>>>>>>>>>>Section 9.1.
>>>>>>>>>>>>>>>>> This is the RECOMMENDED authentication mechanism in
>>>>>>>>>>>>>>>>>BFCP.²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> What are the cases where clients and servers do not
>>>>>>>>>>>>>>>>>need  to be authenticating each other? I know this
>>>>>>>>>>>>>>>>>requirement  and the other SHOULD-level requirements
>>>>>>>>>>>>>>>>>around use of  TLS/DTLS are carried over from RFC 4582,
>>>>>>>>>>>>>>>>>but I¹m  concerned that they aren¹t as strong as they
>>>>>>>>>>>>>>>>>should be.
>>>>>>>>>>>>>>>>> For a conference where the signaling traffic is
>>>>>>>>>>>>>>>>>authenticated and confidentiality and integrity
>>>>>>>>>>>>>>>>>protected, why is it ok for the floor control traffic
>>>>>>>>>>>>>>>>>not to be? Could these requirements be adjusted to
>>>>>>>>>>>>>>>>>require use of TLS/DTLS at least in cases where the
>>>>>>>>>>>>>>>>>signaling is also protected?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Yes, but again, this would be at the expense of adding a
>>>>>>>>>>>>>>>> non backward compatible change from rfc 4582. How about
>>>>>>>>>>>>>>>> saying TLS/DTLS MUST be used for BFCP in such cases,
>>>>>>>>>>>>>>>> while pointing out the rfc
>>>>>>>>>>>>>>>> 4582
>>>>>>>>>>>>>>>> based implementations may not comply (similar to what we
>>>>>>>>>>>>>>>> did with the version field).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> Works for me.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Feel free to make all of these changes and submit a rev
>>>>>>>>>>>>>>> and I¹ll issue the IETF LC.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>>>> = Section 14 =
>>>>>>>>>>>>>>>>> See the point above about ciphersuites. ³Non-null
>>>>>>>>>>>>>>>>> encryption² is not a sufficient minimum baseline, and
>>>>>>>>>>>>>>>>> if the requirements change in Section 7 they should be
>>>>>>>>>>>>>>>>> reflected here as well.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Yep.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>> Editorial nits to be resolved with LC comments:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section 5.1 =
>>>>>>>>>>>>>>>>> ³The version field MUST be set to 1 when using BFCP
>>>>>>>>>>>>>>>>> over a reliable transport, i.e. as in [2].²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I find it a little odd to reference the spec you¹re
>>>>>>>>>>>>>>>>> obsoleting in this sentence, especially since BFCP over
>>>>>>>>>>>>>>>>> a reliable transport is completely specified in this
>>>>>>>>>>>>>>>>> bis document. I would suggest dropping the i.e. clause.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Good catch. This is a carry over from before this draft
>>>>>>>>>>>>>>>> was adopted as a bis version of rfc4582.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>> "The version field MUST be set to 2 when using BFCP
>>>>>>>>>>>>>>>>> over an unreliable transport with the extensions
>>>>>>>>>>>>>>>>> specified in this document.²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The bit about ³with the extensions specified in this
>>>>>>>>>>>>>>>>> document² is extraneous and should be removed.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> "If an endpoint receives a message with an unsupported
>>>>>>>>>>>>>>>>> version field value, the receiving server MUST send an
>>>>>>>>>>>>>>>>> Error message with parameter value 12 (Unsupported
>>>>>>>>>>>>>>>>> Version) to indicate this.²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Use of the word ³server² here makes it sound as if only
>>>>>>>>>>>>>>>>> servers could receive headers with unsupported versions.
>>>>>>>>>>>>>>>>> Should this be ³the receiving endpoint²?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section 6.2.4 =
>>>>>>>>>>>>>>>>> "[23], Section 6.7 provides useful recommendations Š²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The links in the references are not quite right.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section 8.3.2 =
>>>>>>>>>>>>>>>>> s/when fires/when fired/
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section 14 =
>>>>>>>>>>>>>>>>> s/high-jack/hijack/
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> = Section B.1 =
>>>>>>>>>>>>>>>>> "situation where multiple different and
>>>>>>>>>>>>>>>>> non-interoperable would
>>>>>>>>>>>>>>>>> co-
>>>>>>>>>>>>>>>>> exist in the market.²
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> There is a word missing after ³non-interoperable."
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> This should read ³non-interoperable implementations².
>>>>>>>>>>>>>>>> Earlier in that same sentence, ³BFCP over UDP were
>>>>>>>>>>>>>>>>already used² should read ³BFCP over UDP is already being
>>>>>>>>>>>>>>>>used².
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>>> Charles
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>> bfcpbis mailing list
>>>>>>>>>>>>>>> [email-masked]<mailto:[email-masked]>
>>>>>>>>>>>>>>> https://www.ietf.org/mailman/listinfo/bfcpbis
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>    
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>     
>>>>>>>>>>>>>
>>>>>>>>>>>>>      
>>>>>>>>>>>>
>>>>>>>>>>>>       
>>>>>>>>>>>
>>>>>>>>>>>        
>>>>>>>>>>
>>>>>>>>>>         
>>>>>>>>>
>>>>>>>>>          
>>>>>>>>
>>>>>>>>           
>>>>>>>
>>>>>>>            
>>>>>>
>>>>>>          
>>>>
>>>>      
>>>    
>>
>
>_______________________________________________
>bfcpbis mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/bfcpbis

---

From: Christer Holmberg <[email-masked]>
Date: Mon, 21 Sep 2015 18:23:04 +0000

Hi,

>     [RFC4145 <https://tools.ietf.org/html/rfc4145>].

Correct.

And, IF we decide to use define usage of the 'connection' attribute for DTLS, we would change that.

However, a few days ago we sent an e-mail to the MMUSIC list, suggesting that we should NOT use the 'connection' attribute for DTLS. Instead we should define a new attribute (for more details, please see the MMUSIC list).

> I suppose if draft-ietf-mmusic-dtls-sdp pulls in enough from RFC 5763 to make it clear how the DTLS establishment and re-establishment works 
> for the case of which the connection attribute is not used, then we can change the reference from RFC 5763 to draft-ietf-mmusic-dtls-sdp.
>
> The last several updates of draft-ietf-bfcpbis-rfc4583bis have removed supporting text from the draft in favor of pointing to RFC 5763 as the 
> source of truth. I fear that draft-ietf-mmusic-dtls-sdp in its current state does not serve that need for draft-ietf-bfcpbis-rfc4583bis. I value 
> Christer’s thoughts and welcome the opinion of others, especially those who have or are implementing BFCP with DTLS and ICE, which I have not.

Please note that DTLS-SDP does not only define usage of the 'connection' attribute, it also does other things. Maybe more important, it does not state that an address change by default requires a new DTLS association - which is a another 5763 modification.

Regards,

Christer

wrote:

>Hi Charles,
>
>>The problem I see with this is that it is not just a matter of 
>>changing the reference, it is also a matter of changing the normative behavior.
>>If we are to start requiring it, we would need add text to describe 
>>how to address backward compatibility in cases in which the connection 
>I am not familiar with the 5763bis draft. But, even if the DTLS-SDP 
>draft makes updates to 5763, it won't become a 5763bis draft.
>
>Regards,
>
>Christer
> 
>
>
>>of the ideas with the new draft is to also update RFC 5763 to 
>>reference the new dtls-sdp draft.
>>
>>>>then use it  as the basis for Mary, the document shepherd, to 
>>>>provide a proto writeup.
>>>>
>>>> Cheers,
>>>> Charles
>>>>
>>>>
>>>>> When DTLS is used with UDP, the requirements specified in Section 
>>>>> 5 of [13] MUST be followed.
>>>>>
>>>>>
>>>>> Section 10.5
>>>>>
>>>>> OLD
>>>>>> connection for multiple streams - it mainly results from the 
>>>>>> usage of ICE. And, as far as I know, ICE can be used also for BFCP.
>>>>>>
>>>>>>> The discussion is still ongoing, but the outcome will most 
>>>>>>> likely NOT be aligned with the text above.
>>>>>>>
>>>>>>>>>> He is in the process of reviewing. If all goes well with 
>>>>>>>>>> that, we are ready to proceed with proto writeup (Mary) and AD review.
>>>>>>>>>>
>>>>>>>>>> Cheers,
>>>>>>>>>> Charles
>>>>>>>>>>
>>>>>>>>>>>> rfc4583bis be on the agenda of the telechat as well or 
>>>>>>>>>>>> there is still something left for Tom to take care of?
>>>>>>>>>>>>
>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>
>>>>>>>>>>>> Gonzalo
>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Thank you for the review. Please see my thoughts on 
>>>>>>>>>>>>>>>> your comments and questions inline.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> "If an endpoint receives a message with an  
>>>>>>>>>>>>>>>>> unsupported version field value, the receiving server 
>>>>>>>>>>>>>>>>> MUST send an Error message with parameter value 12 
>>>>>>>>>>>>>>>>> (Unsupported
>>>>>>>>>>>>>>>> were thinking in terms of implementations compliant 
>>>>>>>>>>>>>>>> with this bis version.
>>>>>>>>>>>>>>>> Adding
>>>>>>>>>>>>>>>>> I realize this requirement comes from RFC 4582, but 
>>>>>>>>>>>>>>>>> I¹d like to understand why it has not been updated to 
>>>>>>>>>>>>>>>>> be consistent with more current guidance on cipher 
>>>>>>>>>>>>>>>>> suite selection (e.g.,
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> server is received for the transaction, but need not 
>>>>>>>>>>>>>>>>> be monotonically increasing (e.g., a lower, recently 
>>>>>>>>>>>>>>>>> used ID could be re-used once a response is
>>>>>>>>>>>>>>>>> received)
>>>>>>>>>>>>>>>>> If so, why not just require IDs in all 
>>>>>>>>>>>>>>>>> client-initiated transactions to be monotonically increasing?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>      consist of a request from a floor control server 
>>>>>>>>>>>>>>>> to a client and a
>>>>>>>>>>>>>>>> message to the Conference ID for the conference that 
>>>>>>>>>>>>>>>> the client obtained previously.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>receiver distinguish the reception of the next message 
>>>>>>>>>>>>>>>>in a sequence of BFCP messages from a retransmission of 
>>>>>>>>>>>>>>>>a previous message.  Therefore, BFCP entities using an 
>>>>>>>>>>>>>>>> [Question: is there a need to copy the Conference ID 
>>>>>>>>>>>>>>>>and  User ID, if present?]
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> 8.2. Server Behavior
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> ID, the Transaction ID, and the User ID from the 
>>>>>>>>>>>>>>>> request received from the client into the response.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Server-initiated transactions MUST contain a 
>>>>>>>>>>>>>>>>Transaction ID equal to
>>>>>>>>>>>>>>>>same properties as for client-initiated transactions. 
>>>>>>>>>>>>>>>>The server uses the Transaction ID value to match this 
>>>>>>>>>>>>>>>> Yes, but again, this would be at the expense of adding 
>>>>>>>>>>>>>>>> a non backward compatible change from rfc 4582. How 
>>>>>>>>>>>>>>>> about saying TLS/DTLS MUST be used for BFCP in such 
>>>>>>>>>>>>>>>> cases, while pointing out the rfc
>>>>>>>>>>>>>>>> 4582
>>>>>>>>>>>>>>>> based implementations may not comply (similar to what 
>>>>>>>>>>>>>>>> we did with the version field).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>> Works for me.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> obsoleting in this sentence, especially since BFCP 
>>>>>>>>>>>>>>>>> over a reliable transport is completely specified in 
>>>>>>>>>>>>>>>>> this bis document. I would suggest dropping the i.e. clause.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>> Use of the word ³server² here makes it sound as if 
>>>>>>>>>>>>>>>>> only servers could receive headers with unsupported versions.
>>>>>>>>>>>>>>>>already used² should read ³BFCP over UDP is already 
>>>>>>>>>>>>>>>>being used².
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>>> Charles
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>

---

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Mon, 21 Sep 2015 18:50:34 +0000

I see. As this is a moving target, perhaps where we reference RFC 5763 we
can add a note for the RFC editor that draft-ietf-mmusic-dtls-sdp is
expected to add clarifications and make changes to RFC 5763 that should be
considered prior to publication of rfc4583bis.

Cheers,
Charles

On 9/21/15, 11:23 AM, "Christer Holmberg" <[email-masked]>
wrote:

>However, a few days ago we sent an e-mail to the MMUSIC list, suggesting
>that we should NOT use the 'connection' attribute for DTLS. Instead we
>should define a new attribute (for more details, please see the MMUSIC
>list).
>
>> I suppose if draft-ietf-mmusic-dtls-sdp pulls in enough from RFC 5763
>>to make it clear how the DTLS establishment and re-establishment works
>> for the case of which the connection attribute is not used, then we can
>>change the reference from RFC 5763 to draft-ietf-mmusic-dtls-sdp.
>>
>Please note that DTLS-SDP does not only define usage of the 'connection'
>attribute, it also does other things. Maybe more important, it does not
>state that an address change by default requires a new DTLS association -
>which is a another 5763 modification.
>
>Regards,
>
>Christer
>
>
>
>

---

From: Paul Kyzivat <[email-masked]>
Date: Mon, 21 Sep 2015 15:25:43 -0400

ISTM the key question is whether changes should be made to the way bfcp 
over dtls is signaled and established/reestablished, in order to be 
consistent with what is going on with draft-ietf-mmusic-dtls-sdp.

We are in a transition period here. Till now every usage of dtls has 
been treated as a one-off. We are now trying to learn from all that and 
introduce some consistency. And that includes consistently handling some 
of the special cases that often haven't been handled well before, such 
as when re-establishment does/doesn't occur, and how re-establishment at 
different layers is handled.

Certainly there are issues of backward compatiblity with rfc4583 that 
constrain what is done. But ISTM it would be good to try to align these 
things going forward.

	Thanks,
	Paul

---

From: Christer Holmberg <[email-masked]>
Date: Tue, 22 Sep 2015 06:48:09 +0000

Hi,

>I see. As this is a moving target, perhaps where we reference RFC 5763 we can add a note for the RFC editor that draft-ietf-mmusic-dtls-sdp is expected to add clarifications and make changes to RFC 5763 that should be considered prior to publication of rfc4583bis.

I am not sure I understand. I don't think it's up to the RFC editor to make a decision whether the draft should reference DTLS-SDP.

Regards,

Christer

On 9/21/15, 11:23 AM, "Christer Holmberg" <[email-masked]>
wrote:

>However, a few days ago we sent an e-mail to the MMUSIC list, 
>suggesting that we should NOT use the 'connection' attribute for DTLS. 
>Instead we should define a new attribute (for more details, please see 
>the MMUSIC list).
>
>>for the case of which the connection attribute is not used, then we 
>>can change the reference from RFC 5763 to draft-ietf-mmusic-dtls-sdp.
>>
>> The last several updates of draft-ietf-bfcpbis-rfc4583bis have 
>>removed supporting text from the draft in favor of pointing to RFC 
>>5763 as the  source of truth. I fear that draft-ietf-mmusic-dtls-sdp 
>>in its current state does not serve that need for 
>>draft-ietf-bfcpbis-rfc4583bis. I value  Christer’s thoughts and 
>>welcome the opinion of others, especially those who have or are 
>>implementing BFCP with DTLS and ICE, which I have not.
>
>state that an address change by default requires a new DTLS association 
>- which is a another 5763 modification.
>
>Regards,
>
>Christer
>
>
>
>
>>>how to address backward compatibility in cases in which the 
>>>connection attribute is not specified.
>>
>>>> The only change in the new version of rfc4583bis just submitted. 
>>>>And as Charles says, this should be the last missing fix for this 
>>>>draft until next stages in the process at least.
>>>>
>>>> -- Tom
>>>>
>>>>>>exchange specified in [13], Section 5 of [13] MUST be followed 
>>>>>>when using DTLS.
>>>>>>        Informational note: The procedure above is identical to 
>>>>>>the one
>>>>>>>> Thanks for your review and comments. In the BFCP usage, the 
>>>>>>>>DTLS connection is dedicated to the BFCP stream it contains. As 
>>>>>>>>I understand it, the complications around DTLS re-establishement 
>>>>>>>>parameter changes), it would not automatically trigger a new 
>>>>>>>>DTLS connection.
>>>>>>>>
>>>>>>>>
>>>>>>>>>> Checking in on this — has Christer been prompted to review 
>>>>>>>>>> the latest rev of draft-ietf-bfcpbis-rfc4583bis?
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Alissa
>>>>>>>>>>
>>>>>>>>>>>>>> leave, so  it would be great to get this scheduled on 
>>>>>>>>>>>>>> that one. To do that,  the rev needs to be posted today. 
>>>>>>>>>>>>>> The updates are pretty minimal  and are all basically 
>>>>>>>>>>>>>> written up in Charles¹ response to my AD review.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Just wanted to see if this rev might get done in the 
>>>>>>>>>>>>>>> next couple  of days. If so, we could get it on the next 
>>>>>>>>>>>>>>>>>> This seems like it should at least be  noted given 
>>>>>>>>>>>>>>>>>>the MUST-level requirement. The same applies in  
>>>>>>>>>>>>>>>>>>Section 13.7.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>> your suggested note about rfc 4582 implementations 
>>>>>>>>>>>>>>>>> here and in  section 13.7 seems useful to me.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>> Ok
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>>> = Section 7 =
>>>>>>>>>>>>>>>>>> https://tools.ietf.org/html/draft-ietf-uta-tls-bcp-08
>>>>>>>>>>>>>>>>>> #
>>>>>>>>>>>>>>>>>> s
>>>>>>>>>>>>>>>>>> e
>>>>>>>>>>>>>>>>>> c
>>>>>>>>>>>>>>>>>> tion
>>>>>>>>>>>>>>>>>> -4)
>>>>>>>>>>>>>>>>>> .
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>>> = Sections 8, 8.1, 8.2 = It seems like the 
>>>>>>>>>>>>>>>>>> transaction ID requirements regarding 
>>>>>>>>>>>>>>>>>> non-reuse/monotonically increasing IDs are re-stated 
>>>>>>>>>>>>>>>>>> multiple times across these three sections, in 
>>>>>>>>>>>>>>>>>> slightly different ways, to the point where it¹s not clear exactly what they are.
>>>>>>>>>>>>>>>>>> It seems like they are:
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> detail. As such, the transaction ID related 
>>>>>>>>>>>>>>>>> information at the start of Section 8 is superfluous. 
>>>>>>>>>>>>>>>>> I recommend reducing the text in Section 8 to the
>>>>>>>>>>>>>>>>> follow:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 8. Protocol Transactions
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Client-initiated transactions consist of a request 
>>>>>>>>>>>>>>>>> from a client to a floor control server and a response 
>>>>>>>>>>>>>>>>> from the floor control server to the client.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>important to choose a Transaction ID value that lets 
>>>>>>>>>>>>>>>>>the receiver distinguish the reception of the next 
>>>>>>>>>>>>>>>>>message in a sequence of BFCP messages from a 
>>>>>>>>>>>>>>>>>retransmission of a previous message.  Therefore, BFCP 
>>>>>>>>>>>>>>>>>entities using an unreliable transport MUST use 
>>>>>>>>>>>>>>>>>monotonically increasing Transaction ID values (except for wrap-around).
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> 0 when BFCP is used over a reliable transport.  Over 
>>>>>>>>>>>>>>>>>an unreliable transport, the Transaction ID shall have 
>>>>>>>>>>>>>>>>>the same properties as for client-initiated transactions.
>>>>>>>>>>>>>>>>>>before  sending any BFCP message to it or accepting 
>>>>>>>>>>>>>>>>>>any BFCP message from it.
>>>>>>>>>>>>>>>>>> Similarly, floor control servers SHOULD authenticate 
>>>>>>>>>>>>>>>>>>a client before accepting any BFCP message from it or 
>>>>>>>>>>>>>>>>>>around use of  TLS/DTLS are carried over from RFC 
>>>>>>>>>>>>>>>>>>4582, but I¹m  concerned that they aren¹t as strong as 
>>>>>>>>>>>>>>>>>>they should be.
>>>>>>>>>>>>>>>>>> if the requirements change in Section 7 they should 
>>>>>>>>>>>>>>>>>> be reflected here as well.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>> Yep.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>> Good catch. This is a carry over from before this 
>>>>>>>>>>>>>>>>> draft was adopted as a bis version of rfc4582.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>

---

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Tue, 22 Sep 2015 14:04:45 +0000

I view referring to draft-ietf-mmusic-dtls-sdp now instead of RFC 5763 to
be like writing a blank check. Debate is actively occurring on the list,
the normative language in RFC 5763 is expected to be updated in multiple
ways, and backward compatibility with the the normative language provide
in previous version of rfc4583bis is not fully addressed. It seems more
appropriate to me at this stage to continue to refer to RFC 5763 with a
note regarding updating or replacing that reference with one to
draft-ietf-mmusic-dtls-sdp, as determined prior to publication.

Cheers,
Charles 

On 9/21/15, 11:48 PM, "Christer Holmberg" <[email-masked]>
wrote:

>Hi,
>
>>I see. As this is a moving target, perhaps where we reference RFC 5763
>>we can add a note for the RFC editor that draft-ietf-mmusic-dtls-sdp is
>>expected to add clarifications and make changes to RFC 5763 that should
>>be considered prior to publication of rfc4583bis.
>
>I am not sure I understand. I don't think it's up to the RFC editor to
>make a decision whether the draft should reference DTLS-SDP.
>
>Regards,
>
>Christer
>
>
>

---

From: Christer Holmberg <[email-masked]>
Date: Thu, 24 Sep 2015 09:53:47 +0000

Hi Charles,

I am still not sure I understand your suggestion: what is meant by "as determined prior to publication"? When/where/who? :)

Regards,

Christer

-----Original Message-----
From: Charles Eckel (eckelcu) [mailto:[email-masked]] 
Sent: 22. syyskuuta 2015 17:05
To: Christer Holmberg; Tom Kristensen (tomkrist)
Cc: [email-masked]; [email-masked]; Alissa Cooper; Gonzalo Camarillo; Ben Campbell
Subject: Re: [bfcpbis] draft-ietf-bfcpbis-rfc4583bis

I view referring to draft-ietf-mmusic-dtls-sdp now instead of RFC 5763 to be like writing a blank check. Debate is actively occurring on the list, the normative language in RFC 5763 is expected to be updated in multiple ways, and backward compatibility with the the normative language provide in previous version of rfc4583bis is not fully addressed. It seems more appropriate to me at this stage to continue to refer to RFC 5763 with a note regarding updating or replacing that reference with one to draft-ietf-mmusic-dtls-sdp, as determined prior to publication.

Cheers,
Charles 

On 9/21/15, 11:48 PM, "Christer Holmberg" <[email-masked]>
wrote:

>>we can add a note for the RFC editor that draft-ietf-mmusic-dtls-sdp 
>>is expected to add clarifications and make changes to RFC 5763 that 
>>should be considered prior to publication of rfc4583bis.
>
>>> I suppose if draft-ietf-mmusic-dtls-sdp pulls in enough from RFC 
>>>5763 to make it clear how the DTLS establishment and re-establishment 
>>>works for the case of which the connection attribute is not used, 
>>>then we can change the reference from RFC 5763 to draft-ietf-mmusic-dtls-sdp.
>>>
>>attribute, it also does other things. Maybe more important, it does 
>>not state that an address change by default requires a new DTLS 
>>association
>>>>>What if we keep the text and adds this as an additional reference 
>>>>>in the two new text passages proposed by Charles: "... [13], and 
>>>>>the clarifications defined in [draft-ietf-mmusic-dtls-sdp], ...".
>>>>>
>>>>My suggestion is to *only* refer the new dtls-sdp draft. Because, 
>>>>one of the ideas with the new draft is to also update RFC 5763 to 
>>>>update some parts of 5763). It's a generic document, which *any* 
>>>>DTLS usage can then reference.
>>>>
>>>>Regards,
>>>>
>>>>Christer
>>>>
>>>>
>>>>
>>>>>>proposed  resolution, I request we update the draft accordingly 
>>>>>>and then use it  as the basis for Mary, the document shepherd, to 
>>>>>>provide a proto writeup.
>>>>>>
>>>>>> Cheers,
>>>>>> Charles
>>>>>>
>>>>>>
>>>>>>> suggest the following changes to be consistent with what is 
>>>>>>> being proposed in
>>>>>>> MMUSIC:
>>>>>>>
>>>>>>> ------------
>>>>>>> Section 9:
>>>>>>>
>>>>>>> OLD:
>>>>>>>     association MUST support the 'setup' attribute, as defined 
>>>>>>>in [7].
>>>>>>> When DTLS is used with UDP, the 'setup' attribute indicates 
>>>>>>>which of the endpoints (client or floor control server) initiates 
>>>>>>>the DTLS association setup. The requirements for the offer/answer 
>>>>>>>>>I understand it, the complications around DTLS 
>>>>>>>>>re-establishement discussed in MMUSIC result from use of a 
>>>>>>>>>single DTLS connection for multiple RTP and/or SCTP streams. 
>>>>>>>>>Those complications do not exist with the BFCP usage, so I 
>>>>>>>>>think it is sufficient to continue to reference RFC 5763 and 
>>>>>>>>>not use the SDP connection attribute.
>>>>>>>>>
>>>>>>>>>          
>>>>>>>>> There is currently an ongoing discussion in MMUSIC about when 
>>>>>>>>> a DTLS connection is to be re-established.
>>>>>>>>>
>>>>>>>>> For example, there has been a suggestion (by myself) to use 
>>>>>>>>> the SDP connection attribute to explicitly indicate that a new 
>>>>>>>>> DTLS connection needs to be established.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> The draft also says:
>>>>>>>>>
>>>>>>>>>> Christer (cc’d) and I discussed some of the changes offlist 
>>>>>>>>>> in Dallas, and he is to come back to the list with comments 
>>>>>>>>>> after Dallas
>>>>>>>>>> - which is now :)
>>>>>>>>>>
>>>>>>>>>> Cheers,
>>>>>>>>>> Charles
>>>>>>>>>>
>>>>>>>>>>>>> rfc4583 has not had an AD review yet. Richard can 
>>>>>>>>>>>>>hopefully take care of that while I¹m on leave (starting 
>>>>>>>>>>>>>today, actually).
>>>>>>>>>>>>>
>>>>>>>>>>>>>> I have noted that while rfc4582bis in on the agenda of 
>>>>>>>>>>>>>> the March 5th telechat (thanks for handling that!), 
>>>>>>>>>>>>>> rfc4583bis isn't. Tom revised rfc4583bis on February 
>>>>>>>>>>>>>> 20th. Should rfc4583bis be on the agenda of the telechat 
>>>>>>>>>>>>>> as well or there is still something left for Tom to take care of?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Gonzalo
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> next couple  of days. If so, we could get it on the 
>>>>>>>>>>>>>>>> next telechat agenda (March 5).
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Begin forwarded message:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>   
>>>>>>>>>>>>>>>>>>> few questions and comments I¹d like to discuss 
>>>>>>>>>>>>>>>>>>> before issuing the IETF last call. I¹ve also 
>>>>>>>>>>>>>>>>>>> included some editorial nits that should be 
>>>>>>>>>>>>>>>>>>> addressed together with any last call comments.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Comments and questions:
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> = Section 5.1 =
>>>>>>>>>>>>>>>>>>> unsupported version field value, the receiving 
>>>>>>>>>>>>>>>>>>> server MUST send an Error message with parameter 
>>>>>>>>>>>>>>>>>>> value 12 (Unsupported
>>>>>>>>>>>>>>>>>>>compliant with  4582bis (which could certainly 
>>>>>>>>>>>>>>>>>>>account for some of those that  will not support 
>>>>>>>>>>>>>>>>>>>version 2) will therefore never send the  error specified here.
>>>>>>>>>>>>>>>>>>> I¹d like to understand why it has not been updated 
>>>>>>>>>>>>>>>>>>> to be consistent with more current guidance on 
>>>>>>>>>>>>>>>>>>> cipher suite selection (e.g.,
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> from a client to a floor control server and a 
>>>>>>>>>>>>>>>>>> response from the floor control server to the client.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>      When using a reliable transport, 
>>>>>>>>>>>>>>>>>> retransmission timer T1 (see Section 8.3) MUST be 
>>>>>>>>>>>>>>>>>> used for all requests until the transaction is completed.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>client until a response from the server is received 
>>>>>>>>>>>>>>>>>>for the transaction.
>>>>>>>>>>>>>>>>>> The client uses the Transaction ID value to match 
>>>>>>>>>>>>>>>>>>this message with the response from the floor control server.
>>>>>>>>>>>>>>>>>> A client receiving a server-initiated transaction 
>>>>>>>>>>>>>>>>>>over an unreliable transport MUST copy the Transaction 
>>>>>>>>>>>>>>>>>>ID from the request received from the server into the 
>>>>>>>>>>>>>>>>>>response.
>>>>>>>>>>>>>>>>>>message with the response from the floor participant 
>>>>>>>>>>>>>>>>>>or floor chair.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>> Thanks, this is better.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>>>>4582, but I¹m  concerned that they aren¹t as strong 
>>>>>>>>>>>>>>>>>>>as they should be.
>>>>>>>>>>>>>>>>>> Yes, but again, this would be at the expense of 
>>>>>>>>>>>>>>>>>> adding a non backward compatible change from rfc 
>>>>>>>>>>>>>>>>>> 4582. How about saying TLS/DTLS MUST be used for BFCP 
>>>>>>>>>>>>>>>>>> in such cases, while pointing out the rfc
>>>>>>>>>>>>>>>>>> 4582
>>>>>>>>>>>>>>>>> Feel free to make all of these changes and submit a 
>>>>>>>>>>>>>>>>> rev and I¹ll issue the IETF LC.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>>>>>> Alissa
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>  
>>>>>>>>>>>>>>>>>>> = Section 14 =
>>>>>>>>>>>>>>>>>>> encryption² is not a sufficient minimum baseline, 
>>>>>>>>>>>>>>>>>>> and if the requirements change in Section 7 they 
>>>>>>>>>>>>>>>>>>> should be reflected here as well.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Yep.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>>>> unsupported version field value, the receiving 
>>>>>>>>>>>>>>>>>>> server MUST send an Error message with parameter 
>>>>>>>>>>>>>>>>>>> value 12 (Unsupported

---

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Thu, 24 Sep 2015 15:58:11 +0000

As a simple example, we currently refer to rfc4582bis instead of the
eventual RFC. Assuming rfc4582bis does become an RFC, we would want the
RFC editor to update references to it and to RFCxxxx with the actual RFC
number. Similar here, we would want them to check with authors/chairs/ADs
on the state of draft-ietf-mmusic-dtls-sdp to see if we want to replace
our reference to RFC 5763 with a reference to it. This way we can move
forward while draft-ietf-mmusic-dtls-sdp continues to progress as well.
Open to alternate suggestions as well.

Cheers,
Charles

On 9/24/15, 2:53 AM, "Christer Holmberg" <[email-masked]>
wrote:

>Hi Charles,
>
>I am still not sure I understand your suggestion: what is meant by "as
>determined prior to publication"? When/where/who? :)
>
>Regards,
>
>Christer
>
>Cc: [email-masked]; [email-masked];
>Alissa Cooper; Gonzalo Camarillo; Ben Campbell

---

From: Christer Holmberg <[email-masked]>
Date: Fri, 25 Sep 2015 09:21:11 +0000

Hi Charles,

>As a simple example, we currently refer to rfc4582bis instead of the eventual RFC. Assuming rfc4582bis does become an RFC, we would want the RFC editor to update references to it and to RFCxxxx with the actual RFC number. 
>Similar here, we would want them to check with authors/chairs/ADs on the state of draft-ietf-mmusic-dtls-sdp to see if we want to replace our reference to RFC 5763 with a reference to it. This way we can move forward while 
>draft-ietf-mmusic-dtls-sdp continues to progress as well.

I don't think it's the same thing. First you talk about a draft, where the draft name will be replaced with the to-be-assigned RFC number. In the case of DTLS-SDP we are talking about two separate specifications.

Regards,

Christer

On 9/24/15, 2:53 AM, "Christer Holmberg" <[email-masked]>
wrote:

>I view referring to draft-ietf-mmusic-dtls-sdp now instead of RFC 5763 
>to be like writing a blank check. Debate is actively occurring on the 
>list, the normative language in RFC 5763 is expected to be updated in 
>multiple ways, and backward compatibility with the the normative 
>language provide in previous version of rfc4583bis is not fully 
>addressed. It seems more appropriate to me at this stage to continue to 
>refer to RFC 5763 with a note regarding updating or replacing that 
>reference with one to draft-ietf-mmusic-dtls-sdp, as determined prior to publication.
>
>Cheers,
>Charles
>
>>>I see. As this is a moving target, perhaps where we reference RFC 
>>>5763 we can add a note for the RFC editor that 
>>>draft-ietf-mmusic-dtls-sdp is expected to add clarifications and make 
>>>changes to RFC 5763 that should be considered prior to publication of rfc4583bis.
>>
>>>Instead we should define a new attribute (for more details, please 
>>>see the MMUSIC list).
>>>
>>>>5763 to make it clear how the DTLS establishment and 
>>>>re-establishment works for the case of which the connection 
>>>>attribute is not used, then we can change the reference from RFC 
>>>>5763 to draft-ietf-mmusic-dtls-sdp.
>>>>
>>>>>recommendation of continuing to point to RFC 5763 for now may be 
>>>>>the best approach.
>>>>
>>>>>>draft-ietf-mmusic-dtls-sdp, which is going to clarify the 
>>>>>>DTLS-SRTP rules regarding when a new DTLS association must be established.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Christer
>>>>>>
>>>>>>>current  version of the draft. Unless anyone has an issue with 
>>>>>>>the proposed  resolution, I request we update the draft 
>>>>>>>accordingly and then use it  as the basis for Mary, the document 
>>>>>>>shepherd, to provide a proto writeup.
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Charles
>>>>>>>
>>>>>>>
>>>>>>>> I reread the current draft and went through the following 
>>>>>>>> MMUSIC thread on this subject:
>>>>>>>> http://www.ietf.org/mail-archive/web/mmusic/current/msg14631.ht
>>>>>>>> m
>>>>>>>> l
>>>>>>>>
>>>>>>>> As a result, I better understand the issue you are addressing. 
>>>>>>>> I suggest the following changes to be consistent with what is 
>>>>>>>> being proposed in
>>>>>>>> MMUSIC:
>>>>>>>>
>>>>>>>> ------------
>>>>>>>> Section 9:
>>>>>>>>
>>>>>>>> OLD:
>>>>>>>>which of the endpoints (client or floor control server) 
>>>>>>>>initiates the DTLS association setup. The requirements for the 
>>>>>>>>offer/answer exchange specified in [13], Section 5 of [13] MUST 
>>>>>>>>be followed when using DTLS.
>>>>>>>> This way we avoid any potential conflicts with the intent of 
>>>>>>>> RFC 5763, and when clarifications to RFC 5763 are made, they 
>>>>>>>> will be picked up by the BFCP spec.
>>>>>>>>
>>>>>>>> Cheers,
>>>>>>>> Charles
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>>DTLS connection is dedicated to the BFCP stream it contains. 
>>>>>>>>>>As I understand it, the complications around DTLS 
>>>>>>>>>> the SDP connection attribute to explicitly indicate that a 
>>>>>>>>>> new DTLS connection needs to be established.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The draft also says:
>>>>>>>>>>
>>>>>>>>>> The issues above are also holding up the SCTP-SDP draft, so 
>>>>>>>>>> it doesn't only affect BFCPbis :)
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>>
>>>>>>>>>> Christer
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>>> Most of the changes I this recent update to rfc4583bis 
>>>>>>>>>>>>>were inspired by comments and suggested text provided by Christer.
>>>>>>>>>>>>>>>>> I have talked offline with the other authors and Tom 
>>>>>>>>>>>>>>>>>is holding the pen. Tom, do you think you can meet the 
>>>>>>>>>>>>>>>>>time frame below?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Gonzalo
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Sent from my mobile
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> Overall the document appears in good shape. I have 
>>>>>>>>>>>>>>>>>>>> a few questions and comments I¹d like to discuss 
>>>>>>>>>>>>>>>>>>>> This seems a little misleading since RFC 4582 
>>>>>>>>>>>>>>>>>>>>didn¹t specify what to do upon receipt of a message 
>>>>>>>>>>>>>>>>>>>>with a version other than 1.
>>>>>>>>>>>>>>>>>>>> https://tools.ietf.org/html/draft-ietf-uta-tls-bcp-
>>>>>>>>>>>>>>>>>>>> 0
>>>>>>>>>>>>>>>>>>>> 8
>>>>>>>>>>>>>>>>>>>> #
>>>>>>>>>>>>>>>>>>>> s
>>>>>>>>>>>>>>>>>>>> e
>>>>>>>>>>>>>>>>>>>> c
>>>>>>>>>>>>>>>>>>>> tion
>>>>>>>>>>>>>>>>>>>> -4)
>>>>>>>>>>>>>>>>>>>> .
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> How about we keep this minimum requirement, and add 
>>>>>>>>>>>>>>>>>>> a reference to draft-ietf-uta-tls-bcp along with a 
>>>>>>>>>>>>>>>>>>> Server-initiated transactions have different 
>>>>>>>>>>>>>>>>>>> behavior depending on underlying transport:
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>      consist of a single message from a floor 
>>>>>>>>>>>>>>>>>>>control server to a
>>>>>>>>>>>>>>>>>>>      client (notifications).  They do not trigger 
>>>>>>>>>>>>>>>>>>>any response.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>      consist of a request from a floor control 
>>>>>>>>>>>>>>>>>>>server to a client and a
>>>>>>>>>>>>>>>>>>> A client starting a client-initiated transaction 
>>>>>>>>>>>>>>>>>>> MUST set the Conference ID in the common header of 
>>>>>>>>>>>>>>>>>>> the message to the Conference ID for the conference 
>>>>>>>>>>>>>>>>>>> that the client obtained previously.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>common header to a number that is different from 0 
>>>>>>>>>>>>>>>>>>>and that MUST NOT be reused in another message from 
>>>>>>>>>>>>>>>>>>>the client until a response from the server is 
>>>>>>>>>>>>>>>>>>>received for the transaction.
>>>>>>>>>>>>>>>>>>>retransmission of a previous message.  Therefore, 
>>>>>>>>>>>>>>>>>>>BFCP entities using an unreliable transport MUST use 
>>>>>>>>>>>>>>>>>>>over an unreliable transport MUST copy the 
>>>>>>>>>>>>>>>>>>>Transaction ID from the request received from the 
>>>>>>>>>>>>>>>>>>>server into the response.
>>>>>>>>>>>>>>>>>>> client-initiated transaction MUST copy the 
>>>>>>>>>>>>>>>>>>> Conference ID, the Transaction ID, and the User ID 
>>>>>>>>>>>>>>>>>>> from the request received from the client into the response.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>an unreliable transport, the Transaction ID shall 
>>>>>>>>>>>>>>>>>>>have the same properties as for client-initiated 
>>>>>>>>>>>>>>>>>>>transactions.
>>>>>>>>>>>>>>>>>>>The server uses the Transaction ID value to match 
>>>>>>>>>>>>>>>>>>>this message with the response from the floor 
>>>>>>>>>>>>>>>>>>>participant or floor chair.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Thanks, this is better.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> 
>>>>>>>>>>>>>>>>>>>>clients  SHOULD authenticate the floor control 
>>>>>>>>>>>>>>>>>>>>server before  sending any BFCP message to it or 
>>>>>>>>>>>>>>>>>>>>accepting any BFCP message from it.
>>>>>>>>>>>>>>>>>>>> Similarly, floor control servers SHOULD 
>>>>>>>>>>>>>>>>>>>>authenticate a client before accepting any BFCP 
>>>>>>>>>>>>>>>>>>>>message from it or sending any BFCP message to it.
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> BFCP supports TLS/DTLS mutual authentication 
>>>>>>>>>>>>>>>>>>>>between clients and floor control servers, as 
>>>>>>>>>>>>>>>>>>>>specified in Section 9.1.
>>>>>>>>>>>>>>>>>>>>protected, why is it ok for the floor control 
>>>>>>>>>>>>>>>>>>>>traffic not to be? Could these requirements be 
>>>>>>>>>>>>>>>>>>>>adjusted to require use of TLS/DTLS at least in 
>>>>>>>>>>>>>>>>>>>>cases where the signaling is also protected?
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> 4582. How about saying TLS/DTLS MUST be used for 
>>>>>>>>>>>>>>>>>>> BFCP in such cases, while pointing out the rfc
>>>>>>>>>>>>>>>>>>> 4582
>>>>>>>>>>>>>>>>>>> based implementations may not comply (similar to 
>>>>>>>>>>>>>>>>>>> what we did with the version field).
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Works for me.
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> The bit about ³with the extensions specified in 
>>>>>>>>>>>>>>>>>>>> this document² is extraneous and should be removed.
>>>>>>>>>>>>>>>>>>>>

---

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Fri, 25 Sep 2015 22:31:38 +0000

In that case, I prefer Tom’s original suggestion,

If it turns out that draft-ietf-mmusic-dtls-sdp updates RFC 5763, then
there is some redundancy. But that is better than having a hole when it
comes to backward compatibility with existing implementations, which is
what we will have today if we reference draft-ietf-mmusic-dtls-sdp only.

Cheers,
Charles

On 9/25/15, 2:21 AM, "Christer Holmberg" <[email-masked]>
wrote:

>>number. 
>>Similar here, we would want them to check with authors/chairs/ADs on the
>>state of draft-ietf-mmusic-dtls-sdp to see if we want to replace our
>>reference to RFC 5763 with a reference to it. This way we can move
>>forward while 
>I don't think it's the same thing. First you talk about a draft, where
>the draft name will be replaced with the to-be-assigned RFC number. In
>the case of DTLS-SDP we are talking about two separate specifications.
>
>Regards,
>
>Christer
>
>

---

From: Christer Holmberg <[email-masked]>
Date: Mon, 28 Sep 2015 10:07:00 +0000

Hi,

>  Where [13] is a reference to RFC 5763.

If that's something people can agree to, then can live with such compromise :)

Regards,

Christer

If it turns out that draft-ietf-mmusic-dtls-sdp updates RFC 5763, then there is some redundancy. But that is better than having a hole when it comes to backward compatibility with existing implementations, which is what we will have today if we reference draft-ietf-mmusic-dtls-sdp only.

Cheers,
Charles

On 9/25/15, 2:21 AM, "Christer Holmberg" <[email-masked]>
wrote:

>>eventual RFC. Assuming rfc4582bis does become an RFC, we would want 
>>the RFC editor to update references to it and to RFCxxxx with the 
>>actual RFC number.
>>Similar here, we would want them to check with authors/chairs/ADs on 
>>the state of draft-ietf-mmusic-dtls-sdp to see if we want to replace 
>>addressed. It seems more appropriate to me at this stage to continue 
>>to refer to RFC 5763 with a note regarding updating or replacing that 
>>>>draft-ietf-mmusic-dtls-sdp is expected to add clarifications and 
>>>>make changes to RFC 5763 that should be considered prior to 
>>>>publication of rfc4583bis.
>>>
>>>I am not sure I understand. I don't think it's up to the RFC editor 
>>>to make a decision whether the draft should reference DTLS-SDP.
>>>
>>>Regards,
>>>
>>>Christer
>>>
>>>
>>>
>>>>>   associated with an event that requires the DTLS association to 
>>>>>be
>>>>>re-
>>>>>   established.
>>>>>
>>>>>5763 as the  source of truth. I fear that 
>>>>>draft-ietf-mmusic-dtls-sdp in its current state does not serve that 
>>>>>need for draft-ietf-bfcpbis-rfc4583bis. I value  Christer’s 
>>>>>thoughts and welcome the opinion of others, especially those who 
>>>>>have or are implementing BFCP with DTLS and ICE, which I have not.
>>>>
>>>>>>If we are to start requiring it, we would need add text to 
>>>>>>describe how to address backward compatibility in cases in which 
>>>>>>the connection attribute is not specified.
>>>>>
>>>>>>>>>     following the procedures in [7], and the new status will 
>>>>>>>>>be used to
>>>>>>>>>> And, even without ICE we intend to add text saying that a 
>>>>>>>>>>DTLS connection is only re-established if the underlying 
>>>>>>>>>>transport changes.
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>>
>>>>>>>>>> Christer
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>         
>>>>>>>>>>> Hi,
>>>>>>>>>>>
>>>>>>>>>>> There is currently an ongoing discussion in MMUSIC about 
>>>>>>>>>>> when a DTLS connection is to be re-established.
>>>>>>>>>>>
>>>>>>>>>>> This is related to the earlier issue. There is the 
>>>>>>>>>>>discussion about ICE "virtual connections", and that a single 
>>>>>>>>>>>DTLS connection would apply to all ICE candidates associated 
>>>>>>>>>>>with an
>>>>>>>>>>>>>>>>> March 5 will likely be my last telechat before going 
>>>>>>>>>>>>>>>>> on leave, so  it would be great to get this scheduled 
>>>>>>>>>>>>>>>>> on that one. To do that,  the rev needs to be posted today.
>>>>>>>>>>>>>>>>>>>> Good point. I believe we made this a MUST because 
>>>>>>>>>>>>>>>>>>>> we were thinking in terms of implementations 
>>>>>>>>>>>>>>>>>>>> compliant with this bis version.
>>>>>>>>>>>>>>>>>>>> Adding
>>>>>>>>>>>>>>>>>>>>> I realize this requirement comes from RFC 4582, 
>>>>>>>>>>>>>>>>>>>>> but I¹d like to understand why it has not been 
>>>>>>>>>>>>>>>>>>>>> updated to be consistent with more current 
>>>>>>>>>>>>>>>>>>>>> guidance on cipher suite selection (e.g.,
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> I think MUST support TLS_RSA_WITH_AES_128_CBC_SHA 
>>>>>>>>>>>>>>>>>>> for backwards compatibility and SHOULD support the 
>>>>>>>>>>>>>>>>>>> ones listed in the UTA drafts would be ok.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>non-reuse/monotonically increasing IDs are 
>>>>>>>>>>>>>>>>>>>>>re-stated multiple times across these three 
>>>>>>>>>>>>>>>>>>>>>sections, in slightly different ways, to the point 
>>>>>>>>>>>>>>>>>>>>>where it¹s not clear exactly what they are.
>>>>>>>>>>>>>>>>>>>>> It seems like they are:
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>server is received for the transaction, but need 
>>>>>>>>>>>>>>>>>>>>>not be monotonically increasing (e.g., a lower, 
>>>>>>>>>>>>>>>>>>>>>recently used ID could be re-used once a response 
>>>>>>>>>>>>>>>>>>>>>is
>>>>>>>>>>>>>>>>>>>>> received)
>>>>>>>>>>>>>>>>>>>> 8.2 cover the client behavior and server behavior 
>>>>>>>>>>>>>>>>>>>> in detail. As such, the transaction ID related 
>>>>>>>>>>>>>>>>>>>>control server.
>>>>>>>>>>>>>>>>>>>> [Question: is there a need to copy the Conference 
>>>>>>>>>>>>>>>>>>>>ID and  User ID, if present?]
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> 8.2. Server Behavior
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> 0 when BFCP is used over a reliable transport.  
>>>>>>>>>>>>>>>>>>>>Over an unreliable transport, the Transaction ID 
>>>>>>>>>>>>>>>>>>>>shall have the same properties as for 
>>>>>>>>>>>>>>>>>>>>client-initiated transactions.
>>>>>>>>>>>>>>>>>>>>> This is the RECOMMENDED authentication mechanism 
>>>>>>>>>>>>>>>>>>>>>in BFCP.²
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>> What are the cases where clients and servers do 
>>>>>>>>>>>>>>>>>>>>>not need  to be authenticating each other? I know 
>>>>>>>>>>>>>>>>>>>>>this requirement  and the other SHOULD-level 
>>>>>>>>>>>>>>>>>>>>>requirements around use of  TLS/DTLS are carried 
>>>>>>>>>>>>>>>>>>>>>over from RFC 4582, but I¹m  concerned that they 
>>>>>>>>>>>>>>>>>>>>>aren¹t as strong as they should be.
>>>>>>>>>>>>>>>>>>>>> ³The version field MUST be set to 1 when using 
>>>>>>>>>>>>>>>>>>>>> BFCP over a reliable transport, i.e. as in [2].²
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>> I find it a little odd to reference the spec 
>>>>>>>>>>>>>>>>>>>>>you¹re obsoleting in this sentence, especially 
>>>>>>>>>>>>>>>>>>>>>since BFCP over a reliable transport is completely 
>>>>>>>>>>>>>>>>>>>>>specified in this bis document. I would suggest dropping the i.e.
>>>>>>>>>>>>>>>>>>>>>clause.
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>> "The version field MUST be set to 2 when using 
>>>>>>>>>>>>>>>>>>>>> BFCP over an unreliable transport with the 
>>>>>>>>>>>>>>>>>>>>> extensions specified in this document.²
>>>>>>>>>>>>>>>>>>>>>

---

From: "Charles Eckel (eckelcu)" <[email-masked]>
Date: Mon, 28 Sep 2015 15:49:32 +0000

Thanks Christer.

Tom, can you please post the corresponding update to the draft?

Cheers,
Charles

On 9/28/15, 3:07 AM, "bfcpbis on behalf of Christer Holmberg"
<[email-masked] on behalf of [email-masked]>