HA module IP addresses

We are looking to roll out a new Freepbx system now that we have been running test server for a while to get used to it. The system will have around 700 extensions.

We are looking at the HA module and I have a couple of questions.
Firstly we regarding the cluster IP address, can we have more than one cluster IP address? On our test (non HA) Freepbx server we have two IP addresses, one public IP address and one private IP. The internal phones used the private IP on a VLAN, whilst external connections eg SIP used the public IP address.
So for the HA cluster we would need two IP addresses to move between the cluster nodes, is this possible?

Secondary, perhaps this should really be the first question, is HA really what we need or overly complicated? I guess that depends on our own individual requirements, but I’m wondering if we should be looking at our own VMware infrastructure and/or possibly hot standby Freepbx server using the backup module running at regular intervals? Any thoughts on this would be very welcome.


So as far as the floating IP it has to be a single IP address. That is the IP address you use to manage FreePBX and generally what you use to register your phones with. Without the floating IP HA would be useless.

For 700 extensions I would say yes you want HA. The HA module was designed to simplify your disaster recoveries so you do not have to worry about it.

With 700 Extensions, I would imagine that the ROI on having a full HA solution would be well worth it. Not knowing what type of industry you are in, if you are a typical business you could utilize a simple equation, Take your average payroll, figure out what that cost you per hour, and then figure out what an hour of down time will cost you in direct labor expenses… and then figure out what it might cost you again for people to do the work that was supposed to be done during that lost hour… and then add in potential lost revenues from your existing customers/clients not being able to call in, and then add in the potential lost business from potential new clients that can’t get to your staff to learn about your products or services.

If you are a different type of organization, you can use your own metrics to determine your own return on investment…it will be there and then some. With a staff that large you would also have some concerns about personal safety and security, I’m not one to sell on "fear’ but as an employer you have some responsibility to make sure that in the event of an emergency people can communicate, an HA solution gives you that as well.

If you are on the IT side of things, which I figure you are, there is also the reputation of your department at stake, migrating a system with 700 users, or building a new PBX at this scale is not a trivial task. Implementing the extra hardware needed, and license cost for HA is a very small percentage of your total system, and when you compare the cost of your entire system, to what you would get for the same investment from a proprietary platform, I’m pretty sure you will come to the conclusion that the features and flexibility provided by FreePBX HA is going to be well worth it.

Thank you for both replies, some useful advice. Looks like I will continue down the HA route then. I have got as far as installing the first iso, so will licence that shortly, then build the second server.

Since there can only be one “floating” IP address I guess I need to rethink a little on the networking side. Internally we will need 1024 or 2048 private IP’s for the phones etc, cant waste our valuable public IP addresses on that. I guess I will have to look at NATing the floating IP to the outside word for the SIP’s etc.

And I’m yes in the IT department and the general Centos/Networking side of things is straight forward. But help on the Freepbx and Asterisk side of things gratefully received:-)