SIP trunks.

Each card defines one SIP trunk this tenant uses. Trunks are stored in App_Data/<tenant>/appsettings.json · WebPhone:Trunks and read by the SIP bridge.

Label: free-form hint shown in logs and CDRs (primary / backup / voiptalk-uk). The bridge does NOT route by this — routing is by Priority + the inbound/outbound concurrency caps.

Password: typed in the browser, stored plaintext server-side (the bridge needs to recompute SIP Digest responses against the carrier's realm + nonce on every challenge). On disk inside App_Data — protected by NTFS ACLs same as sip-credentials and OIDC keys. Never echoed back to the browser; leave blank on edit to keep the stored one.

From URI: built server-side as sip:<FromUser or Username>@<Host>. If you need a custom URI (different host, params), tick "advanced" and edit the literal FromUri.

Max inbound / outbound: per-direction concurrency caps. -1 = use Max calls as the total; 0 = disable this direction; positive = absolute cap (still limited by total). Example: in=1 out=1 total=1 means at most ONE call either way (not one of each).

Numbers: optional list of DIDs / extensions this trunk owns (e.g. FRITZ!Box **601, **602 or PSTN +436641234567). Comma- or newline-separated. Stage 1 stores them only — future stages can auto-add to the FraudGuard whitelist, drive inbound DID routing, and tag CDRs with the receiving DID. Bridge ignores the field today, so it's safe to fill in now.