G.711 vs Opus Bandwidth
Both tools include IP overhead; they differ in codec families and negotiation reality.
Use G.711/G.729 Bandwidth for classic enterprise/carrier SIP trunks that still standardize on PCM or G.729. Use Opus Bitrate when endpoints negotiate Opus (WebRTC, modern UC). Always multiply by Erlang-sized concurrent calls—not average calls.
G.711/G.729 Bandwidth
On-wire IP rates for legacy telephony codecs including RTP/UDP/IP headers at typical ptimes.
Best for
- ▸ITSP G.711 interconnects
- ▸G.729 WAN compression cases
- ▸QoS class sizing for SBCs
OPUS Bitrate & Bandwidth
Opus payload targets plus IP overhead for modern voice/WebRTC style sessions.
Best for
- ▸WebRTC / modern UC clients
- ▸Variable bitrate planning with peak awareness
- ▸Comparing efficiency vs G.729
How to choose
If the SIP offer/answer must include G.711 for PSTN interop, size G.711 for the worst-case trunk. If both ends guarantee Opus, use the Opus tool and still engineer peaks under VBR. Mixed parks need the higher of the two for QoS.
FAQ
Is Opus always smaller on the wire?
Often at similar quality, but headers dominate at low ptimes—run the numbers.
Where does SIP trunk sizing fit?
SIP Trunk / Erlang B sets concurrency; these tools set Mbps per call.
What about G.722?
Treat as a wideband PCM-class rate in the G.711-family planner mindset, or measure vendor ptime overhead explicitly.