Elastic SIP Trunking — Diagnostics

SIP Error Code Reference

If calls or registrations fail, check the SIP response code:

Verification Checklist

After setting up a trunk, verify the configuration:

1. Check trunk exists: GET /trunks — confirm your trunk appears in the list
2. Check outbound auth is linked (outbound): GET /trunks/{trunkId}/accessControlLists for ACL-based auth, or GET /trunks/{trunkId}/credentialLists for digest auth — confirm your ACL or credential list ID appears
3. Check endpoint exists (inbound): GET /trunks/{trunkId}/endpoints — confirm endpoint with correct IP/port
4. Check phone numbers assigned (inbound): GET /trunks/{trunkId}/phoneNumbers — confirm numbers are listed
5. Wait 60 seconds after any config change before testing
6. Test outbound: Send a SIP INVITE to +1XXXXXXXXXX@{hostname}.pstn.sinch.com
7. Test inbound: Call one of the assigned phone numbers and verify your endpoint receives the INVITE

Common Debugging Steps

"My outbound calls get 403"

1. Check your source IP: curl ifconfig.me
2. List ACLs on the trunk: GET /trunks/{trunkId}/accessControlLists
3. Verify your IP is in one of the linked ACLs (use /32 for exact match)
4. Check the SIP From header uses your trunk domain, not the callee's domain

"My SIP UA can't register"

1. Verify a Credential List is linked to the trunk
2. Confirm a Registered Endpoint (not Static) exists on the trunk
3. Verify the username/password in the Credential List matches the UA config
4. Ensure the UA is sending REGISTER to {hostname}.pstn.sinch.com

"Inbound calls aren't reaching my PBX"

1. Verify the phone number is assigned to the correct trunk
2. Check a SIP Endpoint exists with the correct IP and port
3. If using Registered Endpoints, verify the UA's registration is active
4. Check firewall rules — SIP traffic from Sinch must reach your endpoint