Voiceflex - SIP Trunk
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Voiceflex has been a leading UK provider of voice products for over 10 years. They offer a number of SIP, data and hosted services and we have now tested Voiceflex’s SIP trunking product for use with 3CX 15.5.
Reference Web Address: Voiceflex
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
Below is a short overview of the provider's capabilities and services and whether they’re supported or not:
- CLNS (Clip No Screening): Yes
- Catch All Routing: Yes, static SI per trunk
- Fax in T38: Yes (Bypass - No upscaling)
- CLIR (Number Suppression): Yes
- DTMF via RFC 2833: Yes
- Codec Order: G711U, G711A, G729
- NAT Support: Yes
In order to use Voiceflex 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 Voiceflex.
Setup & Collecting 3CX Configuration Settings
Once you have logged into the portal, go to “Services” → “SIP Accounts”. Here you will see a list of all the accounts you have been allocated by Voiceflex. Make a note of the:
- SIP Trunk ID
- Bearer Number
- SIP Server
as these will be used later in this guide to configure the Voiceflex Trunk in 3CX.
Next press the “Edit” button. Also make note of the value in the “Password” field as that will also be needed later in this guide.
After collecting this information, go to “Services” → “Numbers and Programming”. Here you will see a list of the DIDs you have been allocated by Voiceflex.
Select the DIDs you want to use with your 3CX installation including the “Bearer Number” which you made note of above.
With the DIDs you want to use selected, press on “SIP Trunk”. In the window that will open find the SIP Trunk ID from the list, then press OK.
While you still have DIDs selected, now press “Invite Format” and from the drop-down select “DDI: E.164 (canonical with plus)”, then press OK.
The end result after doing the above should be similar to this:
At this point you have collected all required information are ready to configure your Voiceflex Trunk in 3CX.
Configuring the Trunk with 3CX
The general instructions outlining how to add a new SIP Trunk to your 3CX installation can be found here.
Adding the Trunk
Specifically, to add Voiceflex to 3CX, go to “SIP Trunks” and here press “Add SIP Trunk”. From the “Country” drop-down select UK and then “Voiceflex”. In the “Main Trunk No” field enter the “Bearer Number” that you collected in the previous section of this guide, Setup & Collecting 3CX Configuration Settings, then press OK. The number must be written in the full E.164 format including the plus sign, e.g. “+442033272020”.
In the “General” → “Trunk Details” section, in the “Registrar” field enter the “SIP Server” that you have collected from the Voiceflex Portal.
Additionally, in the “Authentication ID” and “Authentication Password” fields, enter the “SIP Trunk ID” and “Password” values as collected in the Setup & Collecting 3CX Configuration Settings section.
Once you have done the above, press OK at the top of the page and your Voiceflex SIP Trunk will be successfully configured.
Adding Additional DIDs
To associate all other DIDs/Numbers you have in your Voiceflex account with 3CX, what you need to do is go to the “Management Console → SIP Trunks”, double-click on your Voiceflex Trunk and go to the “DIDs” tab.
Here you should already see 1 entry that is the Main Trunk number you have set. Add all other DIDs/Number must be inserted in the E.164 including the plus sign (e.g. +442033272020) and press OK once you have finished.
Creating Inbound Rules
Now that you have associated all your DIDs/Number with your SIP Trunk in 3CX, you can create Inbound Rules to set where calls will be routed when those number are called. Instructions on how to create Inbound Rules can be found here.
When configuring Voiceflex SIP Trunks in 3CX, all numbers should be entered in the full E.164 format including the plus sign otherwise calls will be rejected and call routing might not work as intended.
Outbound Caller ID
Voiceflex SIP Trunks supports Clip No Screening (CNS) which means you can present any number you want when calling outbound.
There are no special instructions regarding Outbound Rules that are required, numbers can be dialed either in the International format (00) or in National format (0).
More information about how to create Outbound Rules and how they work can be found here.