Before you start
Sign in to the Sipflex portal and open the trunk you want to connect. Keep the profile, phone number or username and account-specific credentials visible while you configure your system.
- FreePBX 17 administrator access
- IAX2 username and secret from Sipflex
- UDP 4569 permitted between the systems
- A destination for inbound calls
Use the current Sipflex endpoints.
The SIP registrar is sip.sipflex.co.uk and the IAX2 host is iax.sipflex.co.uk. Usernames and passwords remain account-specific and are shown in your portal.
Configure the connection
- Open Connectivity → Trunks and add an IAX2 trunk.
- Set the trunk name to Sipflex IAX2.
- Enter the peer details below, replacing USERNAME and SECRET.
- Set the registration string to USERNAME:SECRET@iax.sipflex.co.uk.
- Submit and Apply Config.
- Create an outbound route using the new trunk and inbound routes for each Sipflex number.
- Open the Asterisk CLI and confirm iax2 show registry and iax2 show peers report the expected state.
; PEER Details
type=friend
host=iax.sipflex.co.uk
port=4569
username=USERNAME
secret=SECRET
auth=md5
context=from-pstn
trunk=yes
disallow=all
allow=alaw
allow=ulaw
; Registration String
USERNAME:SECRET@iax.sipflex.co.ukFreePBX owns the generated files.
Enter these values through the FreePBX interface. Do not edit iax.conf directly on a FreePBX-managed system because Apply Config can overwrite manual changes.
Verify the service
- Confirm the trunk is registered or that the correct public peer IP is saved in the Sipflex portal.
- Place an outbound test call and check the caller ID presented.
- Call the Sipflex number from another network and confirm it reaches the expected inbound context or route.
- Check two-way audio and RFC4733/RFC2833 DTMF.
Support scope
We can check Sipflex credentials, registration state and provider-side call routing. Your PBX, device, firewall, dial plan and application remain your responsibility.