
In part 1 and 2 on this topic, I’ve been looking at how over the top voice services such as the Signal messenger or the Conversations messenger packetize and send data over the cellular network and the resulting graphs look pretty neat. But which codec is actually used for the voice channel? I’ve been looking a bit into the source code of both messengers and both use WebRTC for the voice channel. But which voice codec is actually negotiated? The Internet ‘knows’ that Opus is used, but is that really so? I decided to have a closer look.
Continue reading Which Voice Codec? OTT Voice Observations – Part 3




