Swisscom Enterprise SIP
On this topic
Swisscom “Enterprise SIP” was implemented in version 15 of 3CX Phone System. The implementation is carried out via an SBC in your Swisscom company network, which is connected via a Lan2Lan (MPLS) VPN connection. This is provided by Swisscom for the term of the agreement. Setup of the Lan2Lan coupling is not part of this guide. 3CX must be installed on the standard SIP port 5060.
Phone Number Format
All phone numbers and DIDs must be transmitted in the E164 number format. Therefore, when setting up the “outgoing numbers” of extensions and the trunk, always keep the + 41 ... Format.
You must also disable the automatic conversion of E164 numbers in 3CX. To do this, go to “Settings ⇒ E164 processing” and uncheck “Process E164 Numbers”.
A prerequisite is that a Lan2Lan VPN connection has been established between your network and the Swisscom SBC. Refer to the Swisscom documentation on how to create this connection. To validate the SBC can be reached, ping the SBC IP given to you by Swisscom to determine connectivity.
Step 1: Create Trunk
In the 3CX management console, navigate to SIP Trunks ⇒ “+ Add SIP Trunk”, select Country “CH” and the provider “Swisscom Enterprise SIP”. Enter the master number (main trunk no.) in the E164 format, in this example “+41438198750”.
After the trunk has been generated, fill in the SBC IP provided to you by Swisscom in the “Registrar” field overwriting only the highlighted text shown in the following screenshot. This means that if the IP given to you by Swisscom is “10.254.152.12”, the Registrar field should be “transport-tcp.10.254.152.12”.
Once you have done this, copy the main number (+ 43 ...) into the “Authentication ID” even if the trunk does not require a logon. This value is used to call CLIR and Special Agreement (CLIP No Screening).
Step 2: Assign DIDs
Switch to the DIDs tab and add all the DIDs used in the E164 format.
Step 3: Outgoing Number
Switch to the “Caller ID” tab and enter the number to be displayed as “default”. This will be sent if no Outbound Caller ID has been set in the extension settings.
You can enter a “Outbound Caller ID” number in “Extension Settings ⇒ General ⇒ Outbound Caller ID”.
The implementation of the Swisscom SBC does not require a NAT device in the traditional sense for the use of this SIP trunk. However, the correct VPN ACL must be set.
3CX does not support the geo position emergency call mode defined by Swisscom. The emergency / emergency call center is selected from the emergency call origin. Use of history info is currently not implemented by 3CX. Outgoing connections are identified and billed on the main number, as configured on the “CLIP special Arrangement” or CLIR connection.
A release for the support of T38 using the 3CX Fax Server has not been granted, since no fallback to G711 Fax is possible. Implementations with analog fax devices via ATA converters (FXS) must be configured as pass-through with T38 and G711. This configuration of the relevant ATA is to be done by the ATA manufacturer itself.
- Inbound Clip - Yes
- Outbound Clip - Yes
- Clip No Screening - Yes
- Calling Line Identification Restriction - Yes