Virtualization is a hot concept in the IT world and seems to be equally hot among Windows communication software vendors. Virtualization is especially compelling when the Hyper-V or VMWare infrastructure is in place.
3CX has been supporting virtualization as a way to achieve disaster recovery and a kind of "multi-tenant" functionality for a while now. In fact 3CX CEO Nick Galea says:
The production system at 3CX runs on Hyper V. We also do our bulktests on Hyper V as well as VMware ESX...
To read more 3CX VM Experience:
pbxnsip, while cautious about latency issue with VM's, is also behind virtualization. pbxnsip notes that because of the compact size of pbxnsip it can failover using virtualization technology in as little as a second!
Microsoft Office Communication Server 2007 R2 also now supports virtualization for some of the servers roles that do not handle realtime services such as voice, video, live meeting and desktop sharing. See the entire article at:
Backing Up Your Hyper-V Infrastructure
We have been reviewing what to recommend to backup a bunch of VM's on one Hyper-V server. Here is a good article on this subject.
Failover Without Virtualization
For the very small business (5-10 deskphones) with very little networking infrastructure implementing virtualization only for failover may very well be an overkill. In this situation a small phone appliance that is easily replaced might make the most sense. pbxnsip has an interesting fanless, noiseless and very low power consumption appliance that might be interesting option.
If you want a simple, Windows based failover solution with no single point of failure and that doesn't depend on any virtualization technology you might want to look at a heartbeat script I've developed to do simple Windows PC or server failover.