Subject: [payload] Comments for RTP Payload Format for the TETRA Audio Codec

From: Andreas Ahland <[email-masked]>
Date: Fri, 15 Jun 2018 13:45:18 +0000

Review Comments for

            RTP Payload Format for the TETRA Audio Codec
                      draft-ietf-payload-tetra-00

2018-06-15 by
Andreas Ahland
[email-masked]

I think it is a good description of how to transport tetra encoded speech over IP.

Review Comments:

Chapter 4.3.3. CTRL: Control bit(5 bits) vs 4.3.6. R: Audio Signal Relevance: Do control bits need evaluation or is this already handled in Audio Signal Relevance? If not,  it should be noted that “stolen” marks a Tetra block as unusable for audio decoding. When encoding Tetra to RTP, all control bits should be set to 0 to announce correct audio data.

Chapter „6. Congestion Control Considerations“ could mention that packet losses have the same effect for audio decoding as if some blocks are marked defective or stolen and thus are not available for audio decoding. It could be noted that Tetra does block encoding and decoding and that each of the 137 bits form a complete block which can be decoded by itself.

Mit freundlichen Grüßen / Best regards

Dr.-Ing. Andreas Ahland

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