Re: [bfcpbis] Alexey Melnikov's Discuss on draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)

[Alexey Melnikov <[e-mail]>]

On Mon, Feb 6, 2017, at 12:32 PM, Ram Mohan R (rmohanr) wrote:
> I have published a new revision addressing all the IESG feedback received
> so far.
> 
> https://tools.ietf.org/html/draft-ietf-bfcpbis-sdp-ws-uri-09
> Diff is here -
> https://www.ietf.org/rfcdiff?url2=draft-ietf-bfcpbis-sdp-ws-uri-09

I cleared my DISCUSS, thank you!

> Regards,
> Ram
> 
> -----Original Message-----
> From: "Ram Mohan R (rmohanr)" <[e-mail]>
> Date: Sunday, 5 February 2017 at 6:35 PM
> To: Alexey Melnikov <[e-mail]>
> Cc: Alissa Cooper <[e-mail]>, Ben Campbell <[e-mail]>,
> The IESG <[e-mail]>, "[e-mail]"
> <[e-mail]>, "[e-mail]"
> <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>,
> "[e-mail]" <[e-mail]>
> Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on
> draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
> 
>     Thanks Alexey,
>     I will publish the revision after fixing the nits you pointed below
>     
>     Ram
>     
>     -----Original Message-----
>     From: Alexey Melnikov <[e-mail]>
>     Date: Saturday, 4 February 2017 at 10:51 PM
>     To: "Ram Mohan R (rmohanr)" <[e-mail]>
>     Cc: Alissa Cooper <[e-mail]>, Ben Campbell
>     <[e-mail]>, The IESG <[e-mail]>,
>     "[e-mail]"
>     <[e-mail]>, "[e-mail]"
>     <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>,
>     "[e-mail]" <[e-mail]>
>     Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on
>     draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>     
>         Hi Ram,
>         
>         > On 30 Jan 2017, at 05:30, Ram Mohan R (rmohanr) <[e-mail]> wrote:
>         > 
>         > Hi Alexey/all,
>         > 
>         > Please find the diffs with the changes to use single attribute. This diff also has other comments from Ben, Kathleen incorporated.
>         
>         This looks much better, thank you!
>         
>         You have introduced a typo in one place (search for
>         "wwebsocket").
>         
>         Best Regards,
>         Alexey
>         
>         > Regards,
>         > Ram
>         > 
>         > -----Original Message-----
>         > From: "Ram Mohan R (rmohanr)" <[e-mail]>
>         > Date: Thursday, 19 January 2017 at 9:30 AM
>         > To: Alissa Cooper <[e-mail]>
>         > Cc: Alexey Melnikov <[e-mail]>, The IESG <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>, "[e-mail]" <[e-mail]>
>         > Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         > 
>         >    Hi Alissa,
>         > 
>         >    I don’t have a strong opinion on this. Either way (having a single attribute or two different SDP attributes) would work.
>         > 
>         >    Implementations can still retrieve the value (URI) of that attribute and based on the proto line (TCP/WS/BFCP or TCP/WSS/BFCP) match the URI against ws or wss schema defined in RFC6455.  I would expect such a validation to happen across layers.
>         >    The SDP stack parser to look at the proto line transport value (TCP/WS/BFCP or TCP/WSS/BFCP) and check for presence of a=websocket-uri attribute. The value of this attribute (ws or wss schema) can be passed *as is* to the application (in this case BFCP client application) which will validate it against the schema in RFC 6455.
>         > 
>         >    I am OK to incorporate this comment to have a single SDP attribute. 
>         > 
>         >    Regards,
>         >    Ram
>         > 
>         >    -----Original Message-----
>         >    From: Alissa Cooper <[e-mail]>
>         >    Date: Thursday, 19 January 2017 at 1:58 AM
>         >    To: "Ram Mohan R (rmohanr)" <[e-mail]>
>         >    Cc: Alexey Melnikov <[e-mail]>, The IESG <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>, "[e-mail]" <[e-mail]>
>         >    Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         >    Resent-From: <[e-mail]>
>         >    Resent-To: <[e-mail]>, <[e-mail]>
>         >    Resent-Date: Thursday, 19 January 2017 at 1:58 AM
>         > 
>         >        Hi Ram,
>         > 
>         >        I had some further conversation with Alexey on the side and wanted to come back to a question he posed: is there a reason why a=ws-uri and a=wss-uri both need to be specified? Why can’t a single label be specified, say a=websocket-uri, and then have normative language requiring the scheme in the URI itself to match what’s in the associated m-line (ws:// for TCP/WS/BFCP and wss:// for TCP/WSS/BFCP)? Won’t it be more efficient for implementations to grab the URI itself anyway and check that the scheme matches the m-line?
>         > 
>         >        Thanks,
>         >        Alissa
>         > 
>         >> On Jan 17, 2017, at 9:40 AM, Ram Mohan R (rmohanr) <[e-mail]> wrote:
>         >> 
>         >> Alissa,
>         >> 
>         >> I am fine with the proposed text.
>         >> 
>         >> Thanks,
>         >> Ram
>         >> 
>         >> -----Original Message-----
>         >> From: Alissa Cooper <[e-mail]>
>         >> Date: Tuesday, 17 January 2017 at 8:07 PM
>         >> To: Alexey Melnikov <[e-mail]>
>         >> Cc: The IESG <[e-mail]>, "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>, "[e-mail]" <[e-mail]>, "Ram Mohan R (rmohanr)" <[e-mail]>
>         >> Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         >> 
>         >>   Alexey, would the following changes clarify things?
>         >> 
>         >>   Section 4.1
>         >>   OLD
>         >>   the server side, which could be either
>         >>      the offerer or answerer, MUST add an "a=ws-uri" or "a=wss-uri"
>         >>      attribute in the media section
>         >>   NEW
>         >>   the server side, which could be either
>         >>      the offerer or answerer, MUST add an "a=ws-uri" or "a=wss-uri”
>         >>      attribute (but not both) in the media section
>         >> 
>         >>   Section 4.3
>         >>   OLD
>         >>   If the answers assigns SDP "setup" attribute with "passive", then it
>         >>      MUST have a URI in either "a=ws-uri" or "a=wss-uri" attribute
>         >>      depending on whether the application uses WebSocket or
>         >>      secureWebSocket.
>         >>   NEW
>         >>   If the answers assigns SDP "setup" attribute with "passive", then it
>         >>      MUST have a URI in either "a=ws-uri" or "a=wss-uri" attribute
>         >>      (but not both) in the media section, depending on whether the application uses WebSocket or
>         >>      secureWebSocket.
>         >> 
>         >>   Ram, would you be okay with those clarifications?
>         >> 
>         >>   Alissa
>         >> 
>         >> 
>         >>> On Jan 16, 2017, at 10:09 AM, Ram Mohan R (rmohanr) <[e-mail]> wrote:
>         >>> 
>         >>> Hi Alexey,
>         >>> 
>         >>> -----Original Message-----
>         >>> From: Alexey Melnikov <[e-mail]>
>         >>> Date: Monday, 16 January 2017 at 8:25 PM
>         >>> To: "Ram Mohan R (rmohanr)" <[e-mail]>, The IESG <[e-mail]>
>         >>> Cc: "[e-mail]" <[e-mail]>, "[e-mail]" <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>, "[e-mail]" <[e-mail]>
>         >>> Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         >>> 
>         >>>  Hi Ram,
>         >>> 
>         >>>>  On Mon, Jan 16, 2017, at 02:49 PM, Ram Mohan R (rmohanr) wrote:
>         >>>> Hi Alexey,
>         >>>> 
>         >>>> Please see inline <Ram>
>         >>>> 
>         >>>> -----Original Message-----
>         >>>> From: Alexey Melnikov <[e-mail]>
>         >>>> Date: Monday, 16 January 2017 at 7:57 PM
>         >>>> To: "Ram Mohan R (rmohanr)" <[e-mail]>, The IESG <[e-mail]>
>         >>>> Cc: "[e-mail]"
>         >>>> <[e-mail]>, "[e-mail]"
>         >>>> <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>,
>         >>>> "[e-mail]" <[e-mail]>
>         >>>> Subject: Re: [bfcpbis] Alexey Melnikov's Discuss on
>         >>>> draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         >>>> 
>         >>>>  Hi Ram,
>         >>>> 
>         >>>>>  On Mon, Jan 16, 2017, at 06:09 AM, Ram Mohan R (rmohanr) wrote:
>         >>>>> Hi Alexey,
>         >>>>> 
>         >>>>> Thanks for your feedback. Please see inline <Ram>
>         >>>>> 
>         >>>>> -----Original Message-----
>         >>>>> From: bfcpbis <[e-mail]> on behalf of Alexey Melnikov
>         >>>>> <[e-mail]>
>         >>>>> Date: Saturday, 14 January 2017 at 3:49 AM
>         >>>>> To: The IESG <[e-mail]>
>         >>>>> Cc: "[e-mail]"
>         >>>>> <[e-mail]>, "[e-mail]"
>         >>>>> <[e-mail]>, "Charles Eckel (eckelcu)" <[e-mail]>,
>         >>>>> "[e-mail]" <[e-mail]>
>         >>>>> Subject: [bfcpbis] Alexey Melnikov's Discuss on
>         >>>>> draft-ietf-bfcpbis-sdp-ws-uri-08: (with DISCUSS and COMMENT)
>         >>>>> 
>         >>>>>  Alexey Melnikov has entered the following ballot position for
>         >>>>>  draft-ietf-bfcpbis-sdp-ws-uri-08: Discuss
>         >>>>> 
>         >>>> 
>         >>>>>  ----------------------------------------------------------------------
>         >>>>>  DISCUSS:
>         >>>>>  ----------------------------------------------------------------------
>         >>>>> 
>         >>>>>  This is generally a well written document, but I have a small list of
>         >>>>>  issues that I would like to discuss before recommending its approval:
>         >>>>> 
>         >>>>>  1) Are a=ws-uri and a=wss-uri mutually exclusive? (Section 4.3 is a
>         >>>>>  good
>         >>>>>  place to mention what to do if both are specified).
>         >>>>> 
>         >>>>> <Ram> Yes kind of. In a given media line (m= line) we will either have
>         >>>>> a=ws-uri or a=wss-uri. That said a response from a BFCP server using
>         >>>>> webSocket as a transport can
>         >>>>> have two media lines one with ws and other with wss. Something like:
>         >>>>> 
>         >>>>> Answer (server):
>         >>>>> m=application 50000 TCP/WSS/BFCP *
>         >>>>> a=setup:passive
>         >>>>> a=connection:new
>         >>>>> a=wss-uri:wss://bfcp-ws.example.com?token=3170449312
>         >>>>> m=application 50000 TCP/WS/BFCP *
>         >>>>> a=setup:passive
>         >>>>> a=connection:new
>         >>>>> a=ws-uri:ws://bfcp-ws.example.com?token=3170449312
>         >>>> 
>         >>>>  [Alexey]: This is exactly my problem, you should specify how a
>         >>>>  recipient
>         >>>>  should handle your example above. If you only have 1 attribute, the
>         >>>>  problem goes away entirely.
>         >>>> 
>         >>>> <Ram> in the above case, they are still two different m= lines. The
>         >>>> receiver (after offer/answer is done) of this SDP connects to the URI
>         >>>> mentioned in that m= line. 
>         >>>> Note I just re-used the same URL/port in the example above. If there are
>         >>>> multiple m=application media lines (they will be for different
>         >>>> applications) being negotiated in SDP, one application may use secure WS
>         >>>> and other application may use non-secure WS. The client after it receives
>         >>>> the answer SDP will just setup the connection to the URI specified in the
>         >>>> attribute.  
>         >>> 
>         >>>  Sorry, I was thinking about different example:
>         >>> 
>         >>>  m=application 50000 TCP/WSS/BFCP *
>         >>>     a=setup:passive
>         >>>     a=connection:new
>         >>>     a=wss-uri:wss://bfcp-ws.example.com?token=3170449312
>         >>>     a=ws-uri:ws://bfcp-ws.example.com?token=3170449312
>         >>> 
>         >>>  You have 2 conflicting URIs for the same m= line. Is this possible?
>         >>> 
>         >>> <Ram> No this is not possible. If the transport is TCP/WSS/BFCP we should have only a=wss-uri. If transport is TCP/WS/BFCP we should have only a=ws-uri.
>         >>> 
>         >>> Regards,
>         >>> Ram
>         >>> 
>         >>>> I don’t see any problem in here.  
>         >>>> 
>         >>>> Regards,
>         >>>> Ram
>         >>>> 
>         >>>>>  Why not a single attribute, considering that both ws: and wss: URIs
>         >>>>>  are
>         >>>>>  possible?
>         >>>>> 
>         >>>>> <Ram> I would still prefer two attributes. We just followed the
>         >>>>> convention / approach that was used in [RFC6455].  
>         >>>> 
>         >>>> 
>         >>> 
>         >>> 
>         >> 
>         >> 
>         >> 
>         > 
>         > 
>         > 
>         > 
>         > 
>         > <Diff_ draft-ietf-bfcpbis-sdp-ws-uri-08.txt - draft-ietf-bfcpbis-sdp-ws-uri-09.txt.html>
>         > <draft-ietf-bfcpbis-sdp-ws-uri-09.txt>
>         
>         
>     
>     
>