What gateway is my VOIP phones using

Hi all, might be a basic question, we have 2 gateways in the office.
We have an NBN router and a dedicated 20/20 copper connection.

all IP addresses on workstations and VOIP phones connect to our 20/20 as the default gateway.
our freepbx box has a static IP address and is using the NBN router as the gateway.
Ports are open on the NBN Router only

Because the phones are using as the gateway, are voip calls going through 20/20 connection or NBN?.


That depends on which internet connection your PBX is using to connect to your VoIP provider. Are the two internal networks completely isolated? How are your two internet connections connected to your internal network? You will have to explain your network topology with more detail if we are going to understand it

Your VoIP calls are going through your PBX and whatever internet connection it’s using to talk to your voice service providers.

So the default gateway on the phones doesn’t determine which internet connection the calls go out on. Sip traffic is going through your PBX.

Which question are you actually asking?

Your phones can use your PBX as their default gateway, since they communicate with the PBX and nothing else. Your PBX communicates with something else to connect those phones to the outside world. A common misconception that many people new to Asterisk systems share is that the phone is connected to the phone at the remote end. While being a perfectly reasonable mindset in the older technologies (and Asterisk isn’t really any longer a “new” technology) the way that your system works is that your phones connect to the Asterisk server and the server connects to the rest of the world.

Now, to figure out the rest of your configuration, you need to look at the trunks and the outbound routes in your configuration. The network setting for the PBX server (which you should be able to get from the Sysadmin module in the PBX) will also help you understand how your system is connected to the rest of the world.

Thanks all who answered,

Avayax seem to answer what i was wanting to know.

VOIP Phones are using DHCP, default gateway on DHCP Server is using gateway 1
PBX Box is using a static IP within the same network, but is configured to use gateway 2.
My question was, as the phones are configured to use gateway 1 and PBX box configured to use Gateway 2, which gateway is actually being used.

As Avayax suggested, So the default gateway on the phones doesn’t determine which internet connection the calls go out on. Sip traffic is going through your PBX.


So are all your questions answered?

There is nothing particularly unusual about your setup.

The phones are sending all SIP traffic to your PBX. If you haven’t configured any specific static routes on there, it sends all traffic out through its default gateway.
If the PBX and the phones are on the same LAN, the phones don’t need to send SIP traffic through their default gateway.
If the phone accesses the internet for other reasons, such as checking a time server or downloading firmware from the internet, then that traffic goes through the gateway you have configured on your phone. If phones and PBX are on different networks, then also for SIP.

yes the question was answered, i knew it was a pretty basic setup, i just wanted to clarify the gateway question.
Thanks Avayax for the info, and thank you to the others who responded.