Re: [rtcweb] Data Channel Protocol: Data before DATA_CHANNEL_ACK

[Peter Thatcher <[e-mail]>]

On Mon, Feb 10, 2014 at 11:55 AM, Christer Holmberg <
[e-mail]> wrote:

> Hi Peter,
>
> > If you have to wait for the ACK, it's one more RTT you have to wait
> before you can send data.  We've already
> > got many RTTs form ICE and DTLS and what's built into SCTP.  We
> originally didn't have an ACK message at all, in
> > large part because we didn't want more RTTs.  The ACK was put in to
> handle the edge case of unordered data arriving
> > before the OPEN message.  But we added it in a way that it doesn't add
> more RTTs.
>
> But, you may not even know whether I support the protocol you are sending.
> What should I do if I don't like/support what you send?
>
>
​The signalling is up to the application to define.  If your application
wants to send a message from the receiver to the sender saying "I support
X" or "please send me X", then by all means​ add that to your application,
and don't call channel.send() until the sender knows it should send.



> I think it would be useful to have a REJ message, so that I can explicitly
> tell you that I don't want what you send - rather than me reseting the
> stream, or me not sending an ACK and hope that you will eventually stop
> sending data.
>

​​The signalling is up to the application to define.  If your application
wants to send a message from the receiver to the sender saying "I don't
support X" or "please don't send me X", then by all means​ add that to your
application, and don't call channel.send() if the receiver says it doesn't
want the message.


I think what is already in the standard is sufficient for your use case.
 You just need to add a little application-specific signalling.  I don't
think the in-band signalling is the right place to put things like this.



>
> Regards,
>
> Christer
>
>