VoIP glossary
What is Opus?
Opus is an open, royalty-free audio codec that adapts its bitrate from about 6 to 510 kbit/s and supports wideband voice, used widely in WebRTC and modern softphones.
Opus explained
Opus handles packet loss and changing bandwidth better than older codecs, which is why browsers and apps use it by default. At typical voice settings it sounds noticeably clearer than G.711 because it carries a wider range of frequencies.
The catch is that the public phone network does not support Opus. A call from an Opus softphone to a mobile number is transcoded to G.711 or G.729 somewhere along the way, so callers only get the wideband benefit on internal or app-to-app calls.
Example
Two agents on WebRTC softphones talk over Opus in wideband. When one of them calls a customer’s landline, the PBX transcodes to G.711 for the trunk.
Put it into practice
Prepaid SIP trunks and wholesale routes from $200. Ask sales for rates or the NOC for a technical answer.