[codec] Frames to Packets in draft-ietf-codec-opus-07?

"Christian Hoene" <hoene@uni-tuebingen.de> Mon, 25 July 2011 16:10 UTC

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From: "Christian Hoene" <hoene@uni-tuebingen.de>
To: <codec@ietf.org>, <payload@ietf.org>
Date: Mon, 25 Jul 2011 10:23:55 -0400
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Subject: [codec] Frames to Packets in draft-ietf-codec-opus-07?
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I was wondering why the draft-ietf-codec-opus-07 draft has feature to
concatenate multiple codec frames to packets. At the same time,
draft-spittka-payload-rtp-opus-00 does not support to place multiple codec
entities in on RTP packet.

As a consequence, the maximal size of an Opus packet is limited to 120ms.
Especially, on low rate links this might be too low. Also, on links with a
high packet overhead (such as IPsec or IEEE 802.11b WLAN), this limits seems
to be too.

I would suggest to either

1) Remove the concatenation from draft-ietf-codec-opus-07 and add it to


2) Add a second concatenation feature to the payload spec.

With best regards,


Dr.-Ing. Christian Hoene, University of Tübingen, Computer Science, Chair of
Communication Networks, Research Group Interactive Communication Systems
Sand 13, 72076 Tübingen, Germany, Tel +49 7071 2970532,