Spitfire - SIP Trunk
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Spitfire is one of the UK’s leading Business SIP providers, offering a reliable and cost effective SIP Trunk solution for businesses across the UK.
Reference Web Address: Spitfire
Before configuring the SIP trunk it is required to go through the following checklist and make changes where necessary:
- NAT (when used) created to 3CX
- Firewall Checker passed
- Firewall SIP ALG checked and if present disabled
Further setup information can be found in our Academy: 3CX Academy Basic course
Some providers gained support and compatibility with 3CX on a specific product version. It is advisable to always run the latest version of 3CX to ensure ongoing compatibility.
Minimum 3CX Version: 3CX Phone System 15.5 SP1
Below is a short overview of the provider's capabilities and services and whether they’re supported or not:
- CLNS (Clip No Screening): No
- Catch All Routing: Yes, static SI per trunk
- Fax in T38: No
- Fax in Audio: No
- CLIR (Number Suppression): Yes
- DTMF via RFC 2833: Yes
- Codec Order: PCMA, PCMU, G729
- NAT Support: Yes
In order to use Spitfire trunks with 3CX, some settings must be made within the provider's portal and some information is required to complete the configuration with 3CX.
The portal can be accessed here with the credentials given to you by Spitfire.
Configuring the Trunk with 3CX
The general instructions outlining how to add a new SIP Trunk to your 3CX installation can be found here.
Go to “SIP Trunks” and select “Add SIP Trunk”
- Select Country: UK
- Select Provider in your Country: Spitfire
- Main trunk number: This will have been provided to you by Spitfire and must be added in the unknown number format (e.g. 441234567891)
- Select OK
Under the “General” tab in the “Authentication” section enter your Authentication ID and password (these will be supplied to you by Spitfire).
“Routing of calls to Main Number”. This is where the calls to the main number will go. If you have just installed 3CX the only extension available will be the operator extension that was created during the setup. You can come back and edit this later.
Once that is setup you need to navigate to the Caller ID tab and add your main trunk under the “Configure Outbound Caller ID” field in National II format (e.g. 1234567891 without the leading 44)
When configuring Spitfire SIP Trunks in 3CX, all DID numbers should be entered in the unknown number format (e.g. 441234567891) as this is the format used by Spitfire to send the numbers in.
All outbound caller ID’s must be presented in the National II format (e.g. 1234567891) otherwise Spitfire will reject the call.
Outbound Caller ID
Spitfire SIP Trunks do not support Clip No Screening which means you cannot present any number you want when calling outbound.
Only DID’s that exist on the trunk can be sent, not numbers from a 3rd party. To do this you will need to format the DDI without the leading zero or “44” for example “1234567891”. Under the “Outbound Caller ID” of the individual extension.
There are no special instructions regarding Outbound Rules that are required.
More information about how to create Outbound Rules and how they work can be found here.
Numbers should be dialed in the International format (e.g. 004481234567891) for international calls or in National II format for national calls.