Re: [rtcweb] I-D Action: draft-ietf-rtcweb-data-channel-07.txt - Some editorial comments on section 5

[Christer Holmberg <[e-mail]>]

Hi,

Some editorial comments:

Q1:

Section 5 says:

	"SCTP as specified in [RFC4960] MUST be used in
   	combination with the extension defined in [RFC3758] and provides the
   	following interesting features for transporting non-media data
   	between browsers:"

I suggest to say:

	"The SCTP extension defined in [RFC3758] MUST be supported, and
     	provides the following features:


Q2:

Section 5 says:

	"Each SCTP user message contains a so called Payload Protocol
   	Identifier (PPID) that is passed..."

I suggest to remove "so called".


Q3:

Section 5 says:

	"This value can be used to multiplex multiple protocols
   	over a single SCTP association.  The sender provides for each
   	protocol a specific PPID and the receiver can demultiplex the
   	messages based on the received PPID."

I think we discussed this earlier. The PPID value CAN NOT (at least not as used by WebRTC) be used to multiplex multiple protocols over a single SCTP association. If you create multiple channels, for multiple protocols, the same PPID values may be used for each protocol.

 The PPID CAN, however, be used within a data channel, e.g. to demultiplex the DCP from channel data.


Q4:

Section 5 says:

	"When using DTLS as the lower layer, only single homed SCTP
   	associations MUST be used, since DTLS does not expose any address
   	management to its upper layer."

I suggest to change "MUST be used" to "are supported".


Q5:

Sometimes you say "SCTP" and sometimes "SCTP as defined in [RFC4960]".

I suggest to e.g. use the reference on the first occurrence, and then only use "SCTP".


Regards,

Christer