As a proof of concept, I set up a 3CX system at work with the goal of moving from our current phone system.
I chose AAPT (TPG wholesale) for the SIP trunks for billing considerations and simplicity of migration, but it wasn't immediately obvious how to get the SIP trunk running, and there was no documentation that I could discover with a thorough google search.
I did locate a few forum postings from others who were trying to do the same thing as me, but none of them suggested that they were successful.
I ultimately got the "unsupported" SIP trunk provider operating properly after going through AAPT's BizPhone SIP Trunking Interoperability Guide and hours of trial and error. We've been using it for about a week now, and I love it.
You're probably wondering why I didn't go with a licenced 3CX SIP trunk supplier. I was convinced I could make it work because I'm stubborn. Furthermore, I was unable to locate any suppliers who matched all of my requirements:
a) Calls to and from local, mobile, and national numbers are charged at a set rate.
b) is located near our office and has a SIP proxy (Brisbane, Australia)
c) a provider large enough to guarantee service levels and redundancy
d) has a self-service portal where I can manage forwarding for unreachable and congested conditions
We are already using AAPT for our business Fibre400 internet and they've been so good to deal with, that I decided I had to use them.
Here's some additional information that I've learned over the product which will also hopefully serve as additional keyword tagging to make the post more discoverable.
AAPT, iiNet, and TPG are all part of the same company and all use the same underlying infrastructure for their OTT (Over The Top) SIP trunks (a.k.a BizPhone). Their OTT SIP trunk is a no-hardware SIP trunk. They have gateway SIP trunk solutions which requires a SIP gateway device on-premises. Their SIP infrastructure is built using BroadWorks. The functionality and interoperability between the 3 carriers is identical with slight changes for domain names for SIP trunk and proxy configuration.
Configuring the SIP trunk:
As for configuring the SIP trunk, choose "Generic" and enter your main trunk number. It's important to note that these need to be the 10-digit phone number (e.g. 07 3000 0000) without the +61. You will receive the registrar/server/gateway and outbound proxy details along with your SIP trunk username and password. In my case, the registrar is bizphone.tpgtelecom.com.au and the SIP proxy is bizphone.tpgtelecom.com.
The authentication ID and password are the username and password supplied by the carrier, and the kind of authentication is register/account based. Enter the outgoing caller ID in the same format as the main trunk number when setting it. If you don't disable "supports re-invite" in options, the call will drop when you try to transfer it to an external number. You should untick all of the advanced settings. My re-register timeout is set to 180 seconds by default. "Use default settings" for "which IP to use in contact SIP and connection SDP fields." The transport protocol must be UDP, the IP mode must be IPV4, and G.711 A-law is the only codec supported. Please contact me through direct messaging if anyone reads this article and go, requires assistance or has concerns regarding this specific use case. I am more than willing to help anyone.
I chose AAPT (TPG wholesale) for the SIP trunks for billing considerations and simplicity of migration, but it wasn't immediately obvious how to get the SIP trunk running, and there was no documentation that I could discover with a thorough google search.
I did locate a few forum postings from others who were trying to do the same thing as me, but none of them suggested that they were successful.
I ultimately got the "unsupported" SIP trunk provider operating properly after going through AAPT's BizPhone SIP Trunking Interoperability Guide and hours of trial and error. We've been using it for about a week now, and I love it.
You're probably wondering why I didn't go with a licenced 3CX SIP trunk supplier. I was convinced I could make it work because I'm stubborn. Furthermore, I was unable to locate any suppliers who matched all of my requirements:
a) Calls to and from local, mobile, and national numbers are charged at a set rate.
b) is located near our office and has a SIP proxy (Brisbane, Australia)
c) a provider large enough to guarantee service levels and redundancy
d) has a self-service portal where I can manage forwarding for unreachable and congested conditions
We are already using AAPT for our business Fibre400 internet and they've been so good to deal with, that I decided I had to use them.
Here's some additional information that I've learned over the product which will also hopefully serve as additional keyword tagging to make the post more discoverable.
AAPT, iiNet, and TPG are all part of the same company and all use the same underlying infrastructure for their OTT (Over The Top) SIP trunks (a.k.a BizPhone). Their OTT SIP trunk is a no-hardware SIP trunk. They have gateway SIP trunk solutions which requires a SIP gateway device on-premises. Their SIP infrastructure is built using BroadWorks. The functionality and interoperability between the 3 carriers is identical with slight changes for domain names for SIP trunk and proxy configuration.
Configuring the SIP trunk:
As for configuring the SIP trunk, choose "Generic" and enter your main trunk number. It's important to note that these need to be the 10-digit phone number (e.g. 07 3000 0000) without the +61. You will receive the registrar/server/gateway and outbound proxy details along with your SIP trunk username and password. In my case, the registrar is bizphone.tpgtelecom.com.au and the SIP proxy is bizphone.tpgtelecom.com.
The authentication ID and password are the username and password supplied by the carrier, and the kind of authentication is register/account based. Enter the outgoing caller ID in the same format as the main trunk number when setting it. If you don't disable "supports re-invite" in options, the call will drop when you try to transfer it to an external number. You should untick all of the advanced settings. My re-register timeout is set to 180 seconds by default. "Use default settings" for "which IP to use in contact SIP and connection SDP fields." The transport protocol must be UDP, the IP mode must be IPV4, and G.711 A-law is the only codec supported. Please contact me through direct messaging if anyone reads this article and go, requires assistance or has concerns regarding this specific use case. I am more than willing to help anyone.
