Docs Carriers and PBXs
Any SIP trunk or PBX
Connect a carrier or PBX that can register with a user name and password, or that sends calls from fixed IP addresses.
Before you start
- Your LiveKit project connected in RelayDock.
- Your static IP and SIP address, from the strip at the top of the panel's Overview.
- From your carrier or PBX: SIP credentials for a registration, or the IP addresses it sends calls from.
Option A: registration
Use this for a carrier account or a PBX extension that devices register to.
On the carrier or PBX side
- Create a SIP account or extension and note its user name and password.
- If registrations are restricted by IP, allow RelayDock's static IP.
- Route the numbers that should reach your agent to this account or extension.
In RelayDock
- Endpoints → Add endpoint → Registration. Pick your PBX under Provider template if it's listed, otherwise Other.
- Fill in Registrar (the SIP address of your carrier or PBX), Transport (TCP or TLS recommended), SIP user name, Password and Number.
- Only if your provider needs them: Auth user name, Domain, Realm and Expires (seconds) under Advanced settings. Leave Source IPs empty; RelayDock finds them from the registrar's DNS.
Option B: trunk
Use this when the carrier sends calls to an address you give it, from a known set of IP addresses.
On the carrier side
- Send calls to the endpoint's SIP address in RelayDock over TCP (port 5060) or TLS (port 5061). UDP on 5060 also works; TCP or TLS is recommended.
- If the carrier authenticates with a user name and password, note them.
- For outbound calls, allow RelayDock's static IP on the carrier side.
In RelayDock
- Endpoints → Add endpoint → Trunk.
- Carrier IP addresses: the addresses or CIDR blocks the carrier sends calls from, /16 or narrower.
- Digest user name and Digest password: only if the carrier authenticates with a user name.
- Numbers (DIDs): the numbers the carrier sends to this trunk, as +E.164.
- Outbound calls: turn on if your agents call out, then fill in the Carrier SIP address and choose IP only or Digest authentication.
Verify
- A registration shows Registered within a few seconds; a trunk has nothing to register.
- Place a Test call to check the outbound path.
- Choose Inbound → Listen for a call and call one of the endpoint's numbers from your phone. If the call doesn't reach your agent, the panel names the reason.
Common problems
| What you see | Why | What to do |
|---|---|---|
| Registration fails with 401 or 403 | The SIP user name or password is wrong, or the account doesn't allow registration from RelayDock. | Update the password on the endpoint page; check that the account is active. |
| Registration times out (408, no response) | The registrar isn't reachable: wrong address, port or transport, or a firewall in between. | Check the registrar and transport. If your provider uses an allow list, add RelayDock's static IP. |
| Inbound check: the carrier's IP isn't allowed | The call came from an address that isn't on the endpoint. | Add the address the check shows to Carrier IP addresses (trunk) or Source IPs (registration). |
| Inbound check: the carrier dialed a number the endpoint doesn't have | The carrier sends the number in a different format, for example without the country code. | Add the number exactly as the check shows it, or change the dial format. |
| Inbound calls stop at 407 | The trunk expects digest authentication and the carrier sends a different user name or password. | Set the same digest user name and password on both sides, or clear them to rely on IP addresses only. |