Manage codecs

Open Menu > Settings > Accounts and select your account. Disable it before editing, then open Advanced SIP settings.

Expand Audio codecs. Wi-Fi and mobile data have separate codec lists.

Expand the list you want to change. Use the checkboxes to enable or disable codecs, and drag the handle at the right of a codec to change its priority. Codecs near the top are preferred; your service and the other endpoint determine which compatible codec is used.

Tap the checkmark to save, then re-enable the account. Use codecs supported by your provider. Video codecs are configured in the separate Video codecs section when video is available for your account and enabled features.