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V15: Multi Line PSTN Gateways

This document outlines the steps which need to be taken prior to upgrading to V15 in case your 3CX installation still has PSTN gateways in place which feature more than one SIP trunk per device (e.g. Patton).

V15 - Multi Line PSTN Gateways





In previous versions of 3CX the phone system was in charge for multi port gateways (ISDN or FXO) to hunt for the PSTN ports. However, after the firmware of the vendors became more capable, 3CX abandoned the idea of multi trunks per single gateway and instead let the gateway build hunt groups over all available ports. The result is a faster outbound call processing and simplified DID management.


The latest version and every upcoming version will have no understanding of multiple trunks per device. In case you would now import a backup from an older version, which still has such devices in place, to V15 the result will be that only the first trunk will be restored with the gateway itself as its bound DIDs. All other lines will not be restored at all. To avoid stale trunk IDs and missing DIDs while upgrading follow the steps below to best migrate out of this while moving to V15 without disappointment!


While still active on V14 prepare to upgrade to V15 with the following steps:

  • Update all Gateway templates from the management console
  • Create a new gateway against these new templates (shown below are the new templates and only these should be used) and finish the setup wizard.
  • Do not generate a new config for the device nor upload it right now to the device!
  • Now having two gateways, copy the DIDs easily from the inbound rules to the new trunk by clicking on each DID in the inbound rules and select the new created gateway also. Repeat this for each SIP account on the gateway.

  • Once completed all the DIDs will be cloned to the new gateway
  • Now create  a backup with both gateways (new and old) as a safety net
  • If you are just about to upgrade, delete the old gateway and take another backup!

Note: Both backups, need to be placed outside the 3CX default folder structure while the PBX will uninstall as it will remove all files within the default folders.

  • Uninstall V14, install V15 and restore the backup with just the one single trunked gateway
  • Once in V15, create the config of the gateway (Sip Trunks -> Your Gateway -> Generate device config)
  • Upload the config into your gateway, which will restart and take the single trunk setup


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