SIP Trunk Registration 403 Forbidden After Terraform Apply in AP-SYD Region

Deploying Genesys Cloud SIP trunks via Terraform provider v1.12.0 in the AP-SYD region. The apply succeeds, but trunks show REGISTRATION_FAILED with HTTP 403 in the admin console. Manual re-entry of credentials in UI works immediately, suggesting a race condition or credential encoding issue in the API payload.

Resource config:

resource "genesyscloud_sip_trunk" "main" {
 name = "prod-trunk-01"
 description = "Primary SIP Trunk"
 sip_trunk_settings {
 host = "sip.provider.com"
 port = 5060
 protocol = "TCP"
 username = var.sip_username
 password = var.sip_password
 outbound_proxy = "proxy.provider.com"
 }
 
 # Attempting to force registration check
 depends_on = [genesyscloud_user.role_assignment]
}

API logs show the POST to /api/v2/sip/trunks returns 201, but subsequent OPTIONS requests from Genesys to the provider fail auth. Suspect the password variable is being double-encoded or the registration timer is too aggressive post-creation. Is there a specific wait logic or API call needed to trigger the initial registration handshake after HCL apply? Terraform state shows no errors.

The 403 error post-apply usually stems from how the Terraform provider handles the initial credential handshake versus the UI’s lazy-loading validation. In the AP-SYD region, specifically, there is a known latency in the OAuth token propagation that can cause the API to reject the registration payload before the carrier-side allowlist is fully active.

When using genesyscloud_sip_trunk, ensure the sip_credential block is explicitly defined and not relying on implicit defaults. The provider sometimes strips trailing slashes or whitespace from the outbound_proxy or auth_realm fields during the PUT request, which carriers interpret as invalid credentials.

Try adding a depends_on block to a dummy data source or a sleep resource to allow the carrier registration window to open before the trunk attempts to register. Alternatively, verify the encryption_protocol setting. If left unset, the provider may default to TLS 1.2, but some APAC carriers require TLS 1.3 for new registrations.

Here is a more robust configuration pattern:

resource "genesyscloud_sip_trunk" "main" {
 name = "prod-trunk-01"
 description = "Production BYOC Trunk AP-SYD"
 
 sip_credential {
 auth_id = var.carrier_auth_id
 password = var.carrier_password
 auth_realm = var.carrier_realm
 outbound_proxy = var.carrier_proxy
 encryption_protocol = "TLS"
 encryption_port = 5061
 }

 outbound_routing {
 default_route = true
 }
}

# Force a slight delay if the carrier is slow to provision
resource "null_resource" "wait_for_provisioning" {
 triggers = {
 trunk_id = genesyscloud_sip_trunk.main.id
 }
 provisioner "local-exec" {
 command = "sleep 10"
 }
}

Check the carrier logs for the exact timestamp of the 403. If it aligns with the Terraform apply time, it is likely a credential mismatch or a missing encryption_protocol field. Re-apply with explicit encryption settings.

The suggestion about OAuth token latency makes sense. In my load tests, I see similar 403s when API calls hit rate limits during bulk provisioning. Try adding a depends_on block to force a 5-second delay after trunk creation. This helps the AP-SYD edge catch up before the SIP registration attempts.