Re: [rtcweb] JSEP/WebRTC API Datachannel question

["Cullen Jennings (fluffy)" <[e-mail]>]

On Apr 15, 2014, at 12:13 AM, Christian Groves <[e-mail]> wrote:

> I'll take a punt that people were thinking about 2 below when data channel was added. In order to clarify that I propose to add the following text to the JSEP draft to clarify this.
> 
> http://tools.ietf.org/html/draft-ietf-rtcweb-jsep-06#section-5.2.1
> Replace:
> "Lastly, if a data channel has been created, a m= section MUST be
>   generated for data. The <media> field MUST be set to "application" and the <proto> field MUST be set to "DTLS/SCTP", as specified in [I-D.ietf-mmusic-sctp-sdp], Section 3; the "fmt" value MUST be set to the SCTP port number, as specified in Section 4.1."
> 
> With:
> /  "Lastly, if createDataChannel has been called a m= section MUST be generated for data. In the case of multiple createDataChannel calls only one m= section is generated. The <media> field MUST be set to "application" and the <proto> field MUST be set to "DTLS/SCTP", as specified in [I-D.ietf-mmusic-sctp-sdp], Section 3; the "fmt" value MUST be set to the SCTP port number, as specified in Section 4.1."/
> 
> New text in http://tools.ietf.org/html/draft-ietf-rtcweb-jsep-06#section-5.2.2:
> (above last paragraph)
> / "If createDataChannel has been called and a m= section has not previously been generated, a m= section MUST be generated for data. In the case of multiple createDataChannel calls only one m= section is generated. The <media> field MUST be set to "application" and the <proto> field MUST be set to "DTLS/SCTP", as specified in [I-D.ietf-mmusic-sctp-sdp], Section 3; the "fmt" value MUST be set to the SCTP port number, as specified in Section 4.1.//
> //
> //If all data channels have been closed, the m= section related to the data channels MUST be marked as recvonly by changing the value of the [RFC3264] directional attribute to "a=recvonly".//"/
> 
> It would also be good to add some text regarding the relationship between a createDataChannel and DCEP DATA_CHANNEL_OPEN I'm not sure if the JSEP draft is the place?
> 
> Also the W3C draft could be updated to indicate the interaction of a createDataChannel with the negotiationneeded event in section 5.2 something along the lines of:
> /7. For the first creation of a RTCDataChannel object fire a negotiationneeded event at connection./
> 
> 
> Regards,
> Christian

I probably need to think about this more but I think that sounds like a pretty reasonable change. One way or another, JSEP needs to be clear about what needs to happen here.