Changes to default 3CX Headers

This article covers modifying the 3CX headers to allow outbound calls to flow correctly through to VoIPnow.

In order for the 3CX PBX to function correctly with outbound calls when using the Hosted Network PAYG or Unlimited SIP Trunks you need to modify the default outbound parameters on the trunk.

If you experience issues with calls being rejected by the VoIPNow server or getting service unavailable messages please modify the below settings in the Outbound Parameters of the trunk:

SIP Field


Contact : User Part

"AuthID" Authentication

From : User Part

"AuthID" Authentication

From : Host Part

"GWHostPort" gateway/provider host/port

Changing the above settings should then allow calls to flow through the platform successfully.

If you still encounter issues with the calls please contact our support team via email at or via phone at 1300-781-148

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