Subject: [rtcweb] Suggestion of text to handle zero-length message issue

From: Justin Uberti <[email-masked]>
Date: Thu, 24 Jul 2014 16:12:10 -0400

In http://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-11#section-6.6,
I suggest the following text:

   The SCTP Payload Protocol Identifiers (PPIDs) are used to signal the
   interpretation of the "Payload data", indicating whether it contains a
   string or binary data. Also, because SCTP does not permit
   zero-length messages, they must be handled specially.

   For normal messages, of nonzero length, the PPID "WebRTC String"
   MUST be used to indicate a JavaScript string encoded in UTF-8, and the
   PPID "WebRTC Binary" MUST be used to indicate JavaScript binary data
   (ArrayBuffer or Blob).

   For zero-length messages, the PPID "WebRTC String Empty" MUST
   be used to indicate an empty Javascript string, and the PPID
   "WebRTC Binary Empty" MUST be used to indicate zero-length binary data.
   In either case, a payload consisting of a single (dummy) zero byte MUST
   be supplied to the SCTP layer on the sending side, and regardless of
   any received payload, these messages must be interpreted as
   empty strings or zero-length binary data, as appropriate, on the
receiving side.

   See Section 8 for details on the exact PPID values.

And in Section 8:

        WebRTC String Empty                      55
        WebRTC Binary Empty                     56

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From: Peter Thatcher <[email-masked]>
Date: Thu, 24 Jul 2014 16:22:06 -0400

Looks good to me.

On Thu, Jul 24, 2014 at 4:12 PM, Justin Uberti <[email-masked]> wrote:
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