Provider codec settings
Codecs determine how the app encodes call audio or video. Your SIP service and the other endpoint must support a common codec for the call. Configure these defaults in the VoIP Provider Portal under SIP settings > Advanced SIP settings.
Choose audio codecs
- Find Wi-Fi audio codecs for calls over Wi-Fi, or Mobile audio codecs for calls over cellular data. Each list is independent.
- Keep Use app defaults if you do not need to override the app’s codec selection. This does not disable audio or force a fixed codec list.
- To set an explicit list, select Choose codecs and priority. Tick only codecs supported by your SIP service. Select at least one audio codec.
- Use the up and down buttons beside selected codecs to change their priority. The Preference line shows the resulting order, with the preferred codec first. The final codec is negotiated with the other end of the call.
- Repeat for the other network, then select Save draft and Submit for approval (or Submit update for approval for an existing listing).
The portal saves the app’s codec names and order for you. You do not need to enter a comma-separated list or edit JSON. Selecting Use app defaults again removes that network’s override when you save.
Codec names
| Portal choice | Meaning and when to select it |
|---|---|
| Opus | Wideband audio with an adaptive bitrate. Enable it if your SIP service supports Opus. |
| G.722 | Wideband audio for HD voice on compatible services. |
| G.711 μ-law (PCMU) | Standard narrowband audio, also called G.711u or u-law. |
| G.711 A-law (PCMA) | Standard narrowband audio, also called G.711a or A-law. |
| G.729 | Low-bitrate narrowband audio. Enable it only if your service supports it. |
| iLBC | Low-bitrate narrowband audio for services that support iLBC. |
| AMR | Adaptive narrowband audio. Requires matching support from your service. |
| AMR-WB | Adaptive wideband audio. Requires matching support from your service. |
If your service’s instructions only say G.711, confirm whether it accepts PCMU, PCMA or both. These are separate choices in the portal. There is no single codec order that suits every provider.
Example: a service supporting both G.711 variants
For a service that accepts PCMU and PCMA and prefers PCMU:
- Set Wi-Fi audio codecs to Choose codecs and priority.
- Tick G.711 μ-law (PCMU) and G.711 A-law (PCMA).
- Move PCMU above PCMA. Leave other codecs unchecked.
- Set the same choices for Mobile audio codecs if the service uses the same codec policy on cellular data.
For a service that also supports and prefers Opus, select Opus and move it above the G.711 options. Keep the fallback codecs your service supports. If it accepts only PCMA, select just PCMA for each custom audio list.
Wi-Fi versus mobile data
The Wi-Fi list does not configure cellular calls. You can use the same supported list for both, or choose a different order for mobile data after testing. Low-bitrate codecs can be useful where bandwidth is limited, but both ends must support them. Do not enable a codec solely because its bitrate is lower.
Use app defaults is available separately for each network. If you customise only Wi-Fi, mobile calls retain the app’s own selection.
Video codecs
Wi-Fi video codecs and Mobile video codecs also have separate controls. The current selectable video codec is H.264. Keep Use app defaults, or choose a custom list and tick H.264 when your service supports it. An empty custom video list offers no video codecs for that network.
Video calls must also be enabled in Video calls and available in the customer’s edition and purchases. Selecting H.264 does not unlock video access.
Check before submitting
- Confirm codec support and preferred order with your SIP platform configuration.
- Test incoming and outgoing calls with two-way audio on Wi-Fi and mobile data.
- Check the negotiated codec in your SIP platform’s call details or logs.
- If calls fail after restricting codecs, check for a common codec at both ends; a successful SIP registration does not prove that media will work.
Approval publishes the settings used for newly added accounts. Existing customer accounts retain their current settings. For changes on an existing account, see Manage codecs in the mobile app.
After submitting, the listing shows Awaiting approval. SessionTalk emails the applicant when the listing is approved and published. See Provider portal and setup for the full application process.