Hello Alex Docs

SIP Trunks Overview

Configure carrier trunks, auth, and DID routing for inbound and outbound calls. Read the SIP Trunks guide in Hello Alex documentation.

Overview

SIP trunking matters when you need direct carrier interoperability while preserving Hello Alex conversation controls.

Trunk connections define registration and channel capacity, enabling telephony transport between carrier and platform.
DID routing then maps inbound numbers to pathways so call behavior remains controllable at the application layer.

Good to know: carrier coordination on capacity and registration policies prevents intermittent call failures.

Trunk inventory status helps teams catch registration issues before they affect routing.

Confirm all active trunks show healthy status before assigning production DIDs.

Each trunk entry surfaces health and readiness, making operational checks straightforward.
New trunks can be added as volume or region requirements expand.
Status: Healthy trunks pass registration checks.
Good to know: channel limits negotiated with carriers should be reviewed before high-volume events.
Operational readiness checks
Capacity expansion planning

Configuration quality directly influences registration stability and call throughput.

Run registration tests after each config change and record baseline health metrics.

Domain and credential setup establishes secure carrier registration for voice transport.
Capacity settings define concurrent channel behavior, aligning technical limits with expected call volume.
SIP domain: Carrier registration endpoint.
Good to know: credential rotation plans should be documented before production go-live.
New trunk onboarding
Credential rotation validation

Routing rules connect telephony entry points to business logic, turning carrier traffic into guided conversations.

Map critical DIDs first and perform real-call validation on each route.

Each DID is mapped to pathway handling, determining what callers experience when they dial that number.
Live test calls confirm the mapping chain from carrier ingress to pathway behavior.
DID: Inbound phone number on the trunk.
Good to know: DID-level routing is useful for business-hours and department-specific intake separation.
Department-based DID routing
Business-hours call segmentation

Validate trunk health, then route one DID to a test pathway before broader production mapping.