I have written before about the load-balanced FusionPBX cluster I offer to the public. Now, I will write about the high availability one. In order try to answer all your possible question, I am writing this article. I hope after a reading you get a clear picture what it is and what it is not a high availability FusonPBX cluster.
So this is a question that I have been asked frequently. I think it is better to put an explanation here and forward everyone.
It is very common to see new VoIP companies startups. But as any startup, the entrepreneurs look for the cheapest option with the best performance and availability. First of all, I must say there is no a 100% fault-free architecture, but we can archive 99.99999% and as many 9's you want. It is all about the money you want to invest.
I will explain an architecture that it can be close to 5 nines, 99.999%. It will depend on the money to implement it fully or just a part of it. Please remember that I am telling you what, not how.
Provisioning is the fact of letting an IP Telephone to pull its configuration form an external entity. When a telephone pulls the information, it will at least this information:
Some other phones are more advanced and they can pull more information, such as shortcuts, display information, tunes, SIP/RTP parameters, etc.
CDR Importer is the element that allows pushing your call details into a database for a post-mortem analysis. For example, Billing.
FusionPBX as a project offers you these things. So, having a Provisioning and CDR Importer server sounds quite easy if you are talking about stand-alone deployments, but in this case, I will write about something more interesting: cluster deployment. Regardless of you have a high-availability or load-balanced cluster, there is a point where you have enough load that you need to take out non-essential VoIP functions out of the main SIP nodes to keep load and service quality at an acceptable level. Moving out of the SIP Cluster Nodes functions such as provisioning or CDR importing is one of the first steps you should do.