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Voice

SIP trunking

Use SIP trunking when your own voice platform handles the conversation. AgentPhone’s hosted/webhook voice modes and SIP routing are different choices for a number’s voice traffic.

Request access

Open SIP trunking in the dashboard. If access is not enabled, request it there. POST /v1/sip-trunks returns 403 until the selected account is enabled; an API key or available credit balance alone does not enable SIP. iMessage-number trunking has separate eligibility, so specify that requirement when requesting access.

Connect your voice platform

  1. Create a trunk in the enabled account and save the returned connection details.
  2. Configure the trunk’s authentication and allowed source addresses as required by your platform. Keep credentials private.
  3. Set the origination destination for calls coming from the phone network to your platform. The termination address is used for calls from your platform to the phone network; these directions are easy to confuse.
  4. In the number’s voice-routing settings, select the trunk. Use a test number you control to check inbound and outbound audio.

The API reference exposes trunk create, list, get, update, and delete operations under /v1/sip-trunks. Supported authentication and settings depend on the account’s trunk configuration; use the returned details rather than assuming a hostname or copying another account’s credentials.

How routing affects agents

A number routed to a SIP trunk cannot also originate a hosted/webhook call through POST /v1/calls. Originate from your SIP platform, or switch the number’s voice routing back to its AgentPhone agent. SMS/iMessage readiness is separate from the voice route.

Troubleshooting

  • 403 on trunk creation: confirm SIP access in the same account/sub-account, including iMessage eligibility when applicable.
  • 422 on call creation: check whether the chosen number is SIP-routed or messaging-only.
  • Inbound reaches the wrong destination: inspect that exact number’s route and the trunk’s origination settings.
  • Authentication or audio failure: compare credentials, allowed IPs, and destination URI with your platform’s configuration; share timestamps and call IDs with support.

Check your account’s Billing page for applicable SIP rates. Calls made through SIP have different rates and behavior from hosted AI calls.