3CX

Add your Vonyx trunk to 3CX as a generic SIP trunk. Your extensions can then call out on your Vonyx numbers, and calls to those numbers ring in 3CX.

Before you start

A Vonyx SIP trunk with a number attached
3CX V20 and access to its Admin console
For an on-premise or self-hosted 3CX: your firewall forwards SIP (UDP 5060) and RTP (UDP 9000–10999, the 3CX default) to 3CX, and SIP ALG is off on your router

Outbound calls

Add the trunk

In the Admin console, go to Admin > Voice & Chat and click Add Trunk. Pick your country, and for the provider pick Generic SIP Trunk (IP-Based). Click OK.

Vonyx checks your username and password on each call. It does not need 3CX to register.

Fill in the General tab

Field	Value
Name	`Vonyx`
Default route	The extension, ring group or IVR that takes calls to numbers you haven't assigned
Create an outbound rule for this SIP Trunk	On
Main Trunk Number	Your Vonyx number, `91XXXXXXXXXX`
Registrar/Server	`43.204.9.41`
Port	`5060`
Auto-discovery	Off
Outbound Proxy	Leave empty
Type of authentication	`Do not require - IP based`
Authentication ID	`your_trunk_username`
Authentication password	`your_trunk_password`
Number of SIM Calls	`1` (your Vonyx channel limit)

Add your numbers

Open the DID Numbers tab, click +Add and enter each Vonyx number on this trunk as 91XXXXXXXXXX.

Set codecs and transport

Open the Options tab:

Under codec priority, keep only G.711 U-law (PCMU) and G.711 A-law (PCMA). Vonyx supports no other codecs.
If advanced options are shown, set Transport Protocol to UDP and leave SRTP Mode at Disabled. Vonyx has no TLS or SRTP.

Click Save.

Create the outbound rule

After you save the trunk, 3CX opens the outbound rule page. (Later you can find it under Outbound Rules > Add.)

Field	Value
Name	`Vonyx India`
Calls to numbers starting with prefix	`91`
Calls to numbers with a length of	`12`
Make outbound calls on	Route 1: the `Vonyx` trunk
Strip Digits / Prepend	Leave empty if users dial `91XXXXXXXXXX`
Outbound Caller ID	Your Vonyx number, `91XXXXXXXXXX`

Click Save. Rules apply top to bottom, so move this rule above any broader rule with Move Up.

Vonyx only accepts one of your Vonyx numbers as caller ID. 3CX uses the main trunk number by default, or the extension's assigned DID. Make sure both are Vonyx numbers.

Inbound calls

Route each number

To an IVR, ring group or queue: Admin > Call Handling, open it and pick the number under Assigned DID Number(s).
To a user: Admin > Users, open the user, and on the General tab pick the number under Assigned DID Number(s).

Numbers you don't assign go to the trunk's Default route.

Point Vonyx at 3CX

In the Vonyx console, open the trunk, turn on Inbound calls, and set Inbound address to your 3CX FQDN or public IP with its SIP port, for example pbx.example.com:5060. See Inbound calls.

Calls arrive from 43.204.9.41. Allow that address on UDP 5060 and on your 3CX RTP ports.

Test the connection

Go to Admin > Voice & Chat and choose Check SIP Trunk for the Vonyx trunk.
For the inbound test, call your Vonyx number from a mobile, answer on a web client extension, and stay on the call for at least 40 seconds.
For the outbound test, click Start, enter a mobile number as 91XXXXXXXXXX, and keep the call up for more than 32 seconds after it's answered.

An IP-based trunk always shows green in Voice & Chat, because 3CX can't tell whether it is up. Only a test call proves it works.

Limitations

DTMF and call transfer are not available on Vonyx yet. IVR menus that need key presses from callers and transfers out to external numbers won't work.
New accounts make 1 call at a time (raise limits).
No TLS or SRTP: use UDP or TCP on port 5060.

Troubleshooting

Problem	Fix
Outbound call fails with `401` or `407`, or is rejected	Check the Authentication ID and password. Check that the caller ID is a Vonyx number.
Outbound call says no route	Check that the outbound rule matches the dialled number (prefix `91`, 12 digits) and sits above broader rules.
Trunk is red and calls skip it	3CX skips unregistered trunks. Use the IP-based provider, not the registration one.
Inbound calls fail in the VoIP Provider Checker	Check the DID is entered as Vonyx sends it, and see the event log under the Dashboard.
Codec mismatch warning	Keep only PCMU and PCMA in the trunk's codec priority.
One-way or no audio	Open your 3CX RTP ports (UDP `9000–10999` by default) to `43.204.9.41`, and turn off SIP ALG. Vonyx sends RTP from UDP `10000–20000`.

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