This FAQ shows the configuration requirements for a SIP Trunk Plus SIP trunk. Before starting you will need to have the details emailed to you when you set up our SIP Trunk Plus SIP trunk.


Step 1: Add a new 'ITSP':



Once you have given the ITSP a suitable name, ensure that:


(a) you have created a new 'SIP Profile'

(b) set 'Use the following servers' to sip.sip-trunking-services.com

(c) set 'Register' to checked

(d) set 'User Name' to the trunk SIP ID / main headline number (supplied when you set up the SIP account)

(e) depending upon your network settings, set 'Force Symmetric NAT Traversal' to 'Auto' (most likely) or 'Off'.

(f) we recommend best practise by setting a short registration timeout trunk setting to make best use of our auto-failover facility so we recommend that you set the ‘registration expiry timeout’ setting (shown as 'Timeout' above) to be equal to 5 minutes (300 seconds) on both on the trunk and for good measure on all end devices also via your phone system’s device profiles / device settings.


Now set up the 'SIP Headers' settings:


(g) set the '"From" domain' to “Use the following Address' and enter sip.500.uk.com



(h) set the '"To" domain' to 'Use the custom domain name' and enter sip.500.uk.com



(i) set the 'Request-URI' to 'Use the custom domain name' and enter sip.500.uk.com



(j) set the 'Caller ID' 'FROM Header' to 'Custom' and enter the SIP ID / main headline number (supplied when you set up the SIP account)

(k) check 'Include optional identity header' and set to 'P-Asserted-Identity' and 'Originating party Caller ID' if diverse outbound CLI presentation / 'spoofing' is required.



(l) set 'Misc' 'Ignore Domain received in From/To SIP headers' to be checked.



Step 2: Set up the trunk 'Authentication' and 'SIP Settings' profile:



(a) set 'Password' to be the trunk password (supplied when you set up the SIP account)

(b) ensure the 'SIP Profile' has 'Do not send re-INVITE...' checked, and that 'Request URI' is selected, then press 'OK'.


Step 3: Ensure that global PBX settings are correctly set:


In addition to the above steps, you should:


(a) ensure the CODEC settings for the PBX are correctly set and reflect the permitted CODEC's in particular ensuring that G729 is not a permitted CODEC.

(b) ensure that any Port and NAT settings match those of the PBX and of any firewall / gateway devices


Step 4: Confirm registration:


Firstly, via the PBX:


(a) via 'View' > 'SIP Servers & ITSP's', ensure that the trunk is shown as registered.


Secondly, via the SIP Trunk Plus portal


(b) log into the SIP Trunk Plus portal.

(c) select the appropriate client account then select the ‘Registrations' tab.You should see that the trunk is registered.  Check that the Port and NAT settings match those of your PBX and of any firewall / gateway devices.


Step 5: Test:


Via a connect device that matches the inbound / outbound rules you have set up for the SIP Trunk Plus trunk:


(a) make an inbound call to the main / headline trunk number.  Ensure two-way voice and ensure the call last more than 60 seconds.

(b) if applicable, make an inbound call to a DDI that is assigned to the trunk but which is not the main / headline trunk number.  Ensure two-way voice and ensure the call last more than 60 seconds.

(c) make an outbound call.  Ensure two-way voice and ensure the call last more than 60 seconds.