RFC 7874: WebRTC Audio Codec and Processing Requirements

Publisher

IETF / RFC Editor

URL

https://www.rfc-editor.org/rfc/rfc7874.html

Published

2016-05-01

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

IETF Trust Legal Provisions; no-redistribution; short excerpts and locators only

Source notes citing this source

• WebRTC endpoints must support RFC 3389 comfort noise for G.711 and for other codecs without built-in CN. Using RFC 3389 CN with Opus is NOT RECOMMENDED. in context
• WebRTC endpoints must implement Opus (per RFC 7587) and G.711 PCMA/PCMU, and Opus decoders must support all Opus modes. in context
• RFC 7874 recommends that endpoints able to process audio above 8 kHz offer Opus before PCMA/PCMU. in context
• WebRTC endpoints must implement Opus (RFC 7587 payload format) and G.711 PCMA and PCMU. in context
• RFC 3389 comfort noise is required for G.711 but not recommended with Opus, which has its own comfort-noise mechanism. in context
• For endpoints handling audio above 8 kHz, RFC 7874 recommends offering Opus before PCMA/PCMU. in context
• RFC 7874 allows DTMF event durations of 40 to 8000 ms (100 ms recommended) with a minimum 30 ms gap between events (70 ms recommended). in context
• WebRTC endpoints must implement audio/telephone-event (RFC 4733) and be able to generate and consume DTMF events 0-9, *, # and A-D. in context

Cite this source record

APA

WarmTransfer. (2016, May 1). RFC 7874: WebRTC Audio Codec and Processing Requirements. WarmTransfer. https://warmtransfer.net/knowledge/sources/rfc-7874-webrtc-audio

BibTeX

@misc{warmtransfer-rfc-7874-webrtc-audio,
  title  = {RFC 7874: WebRTC Audio Codec and Processing Requirements},
  author = {{WarmTransfer}},
  year   = {2016},
  url    = {https://warmtransfer.net/knowledge/sources/rfc-7874-webrtc-audio},
  note   = {IETF / RFC Editor, accessed 2026-09-24}
}