[BUG] Problematic implementation of DCEP

[hector-chou]

Describe the bug
Does it make sense to have per-channel properties (RtcDataChannelInit) about order and reliability, but reference to the same value (SctpSession.packet[1]) indiscriminately while sending messages?

amazon-kinesis-video-streams-webrtc-sdk-c/src/source/Sctp/Sctp.c

Lines 180 to 190 in 2dff44f

	if ((pSctpSession->packet[1] & DCEP_DATA_CHANNEL_RELIABLE_UNORDERED) != 0) {
	pSctpSession->spa.sendv_sndinfo.snd_flags |= SCTP_UNORDERED;
	}
	if ((pSctpSession->packet[1] & DCEP_DATA_CHANNEL_REXMIT) != 0) {
	pSctpSession->spa.sendv_prinfo.pr_policy = SCTP_PR_SCTP_RTX;
	pSctpSession->spa.sendv_prinfo.pr_value = getUnalignedInt32BigEndian((PINT32) (pSctpSession->packet + SIZEOF(UINT32)));
	}
	if ((pSctpSession->packet[1] & DCEP_DATA_CHANNEL_TIMED) != 0) {
	pSctpSession->spa.sendv_prinfo.pr_policy = SCTP_PR_SCTP_TTL;
	pSctpSession->spa.sendv_prinfo.pr_value = getUnalignedInt32BigEndian((PINT32) (pSctpSession->packet + SIZEOF(UINT32)));
	}

It leads to the consequence that we can't have any ordered/reliable channel if we want to have any unordered/unreliable channel, and vice versa.

And is it the reason why we just ignore those properties that comes with DATA_CHANNEL_OPEN message, for channels created by peer? This handler sets nothing about order and reliability.

amazon-kinesis-video-streams-webrtc-sdk-c/src/source/Sctp/Sctp.c

Line 303 in 2dff44f

STATUS handleDcepPacket(PSctpSession pSctpSession, UINT32 streamId, PBYTE data, SIZE_T length)

In the end, why didn't we have DATA_CHANNEL_ACK?

amazon-kinesis-video-streams-webrtc-sdk-c/src/source/Sctp/Sctp.h

Lines 32 to 34 in 2dff44f

	enum {
	DCEP_DATA_CHANNEL_OPEN = 0x03,
	};

SDK version number
v1.7.2

Expected behavior

• Properties about order and reliability should be applied per-channel.
• The same properties in DATA_CHANNEL_OPEN message should be complied.
• We should do DATA_CHANNEL_ACK.

[github-actions]

This is a very old issue. We encourage you to check if this is still an issue in the latest release and if you find that this is still a problem, please feel free to open a new one.

[github-actions]

This is a very old issue. We encourage you to check if this is still an issue in the latest release and if you find that this is still a problem, please feel free to open a new one.

[github-actions]

This is a very old issue. We encourage you to check if this is still an issue in the latest release and if you find that this is still a problem, please feel free to open a new one.

[github-actions]

This is a very old issue. We encourage you to check if this is still an issue in the latest release and if you find that this is still a problem, please feel free to open a new one.