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.
- Asterisk with chan_iax2 enabled
- IAX2 username and secret from the portal
- UDP 4569 permitted between Asterisk and Sipflex
- A restricted inbound dialplan context
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
- Choose IAX2 registration for the trunk in Sipflex.
- Back up iax.conf and extensions.conf.
- Replace USERNAME and SECRET in the registration and peer sections below.
- Keep the inbound context restricted and enable only the codecs you need.
- Reload IAX2 and run iax2 show registry and iax2 show peers.
- Test inbound, outbound and multi-call behaviour before enabling IAX2 trunking for production.
; /etc/asterisk/iax.conf
[general]
bindport=4569
bandwidth=low
disallow=all
allow=alaw
allow=ulaw
register => USERNAME:SECRET@iax.sipflex.co.uk
[sipflex]
type=friend
host=iax.sipflex.co.uk
port=4569
username=USERNAME
secret=SECRET
auth=md5
context=from-sipflex-iax
trunk=yes
disallow=all
allow=alaw
allow=ulaw
; /etc/asterisk/extensions.conf
[from-sipflex-iax]
exten => _X.,1,NoOp(Incoming Sipflex IAX2 call to ${EXTEN})
same => n,Dial(IAX2/your-destination)
same => n,Hangup()
[outbound-sipflex]
exten => _X.,1,Dial(IAX2/sipflex/${EXTEN})
same => n,Hangup()Generate a customised configuration
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.