We optimize the quality of calls by using the Opus codec for audio on Webex Calling. Opus is supported by most clients on the Webex Calling platform and, where possible, is the main codec used for audio calls.

Opus is supported by the Webex client as well as all Multiplatform Phones. Opus is not currently supported by analog telephone adapters and DECT phones on the Webex Calling platform. Opus is also not supported by most PSTN providers and for this reason, G.711 is generally used.

The Opus codec is supported in the following call flows:

  • Webex (desktop) <—> Webex(desktop)

  • Multiplatform Phone <—> Multiplatform Phone

  • Multiplatform Phone <—> Webex (desktop)

  • Multiplatform Phone <—> Auto Attendant

  • Multiplatform Phone <—> Voicemail

  • Webex (desktop) <—> Auto Attendant

  • Webex (desktop) <—> Voicemail

Each codec consumes roughly the same level of bandwidth, which is 70-80kbps for each audio stream. We recommend that customers allow for 100kbps per audio stream that they want to support on their network, keeping in mind that an internal enterprise requires two audio streams (200kbps).