Re: [MMUSIC] Magnus Westerlund's Discuss on draft-ietf-mmusic-t140-usage-data-channel-12: (with DISCUSS)

[Magnus Westerlund <[e-mail]>]

Hi,

I will clear my discuss as I think I strayed beyond the discuss criteria due
missing the sentence in the prior sub-section. 

I think the text would clearer if one took slightly more consideration for under
what conditions in offers or answers the normative language will apply. For
exmaple. When an a=dcmap:3 with a subprotocol="t140" attribute is included ...

This is of course statement dependent and I will not spend my time on suggesting
rewording of all of these. 

Cheers

Magnus


On Tue, 2020-04-07 at 15:05 +0000, Christer Holmberg wrote:
> Hi,
> 
>  ----------------------------------------------------------------------
>  DISCUSS:
>  ----------------------------------------------------------------------
>         
>     >>>    Section 4.1:
>     >>>    
>     >>>       The offerer and answerer MUST NOT include the max-retr or the
> max-
>     >>>       time attribute parameters in the 'dcmap' attribute.
>     >>>    
>     >>>    This is just an example of a issue that is exists in basically all
> of the
>     >>>    RFC 2119 terminolgy using sentences in this section. The
> formulation is that
>     >>>    the offerer or answerer must do something with attributes or
> parameters of
>     >>>    the dcmap attribute. However, it is not stated to be specific to
> the dcmap
>     >>>    attribute that specifically specify something for a T.140 SCTP
> stream. I
>     >>>    think that scope restriction needs to be made more explicit for
> these RFC 2119
>     >>>    statements. Else they would have applicability as soon as one
> support
>     >>>    this specification.
>     >>   
>     >> The last sentence of Section 4 says:
>     >> 
>     >> "This section defines the SDP considerations that are specific to a
> T.140 data
>     >> channel."
>     >
>     > So why is that last and not first? 
> 
>     It is the last sentence of the parent section (4), and covers the
> procedures in the section, including the subsections (4.x). This wording has
> been used multiple times before.
> 
>     But, if you think it is more clear, I could say "The following sub
> sections define the SDP considerations....".
> 
>     > So isn't this all scoped based on that there is an dcsmap line with a
> subprotocol line stating t140 either included in an
>     > offer that one is generating or responding to as an answerer? 
> 
>     Correct, and Section 4.1 describes the SDP details on how to indicate a
> T.140 data channel, using the dcmap attribute.
>     
>     > As you see I am undertain if the sentence is sufficient to scope this
> correctly.
>     > Are there statement that are relevant outside of the scope of actually
> offering
>     > or answering a T140 offer? I think part of the uncertainty is if there
> are
>     > aspect that my be wrongly interpreted if one support T140 but it is not
> actively
>     > included? 
> 
>     The procedures in section 4 (including the sub sections) only apply to
> T140.
> 
>    Regards,
> 
>    Christer
> 
> 
> 
> 
>     Cheers
>     
>     Magnus Westerlund 
>     
>     
>     ----------------------------------------------------------------------
>     Networks, Ericsson Research
>     ----------------------------------------------------------------------
>     Ericsson AB                 | Phone  [phone]
>     Torshamnsgatan 23           | Mobile [phone]
>     SE-164 80 Stockholm, Sweden | mailto: [e-mail]
>     ----------------------------------------------------------------------
>     
>     
>     
-- 
Cheers

Magnus Westerlund 


----------------------------------------------------------------------
Networks, Ericsson Research
----------------------------------------------------------------------
Ericsson AB                 | Phone  [phone]
Torshamnsgatan 23           | Mobile [phone]
SE-164 80 Stockholm, Sweden | mailto: [e-mail]
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