In my opinion, Axon is a high quality product. The price ($0) is also an added bonus. However, Axon is simply the base call management system, for everything else (e.g. Music on Hold, Call Recording, Auto Attendant, Voice Mail, Call Conferencing etc.) you are required to purchase additional modules/programs (such as VRS, IMS, IVM, Quorum).
Groups/Queues work well, there are several options allowing you to play custom messages, music, set delay times for different extensions (e.g. ring phone 1 for 5 seconds, if not answered, keep ringing Phone 1 and also ring Phone 2) etc.
I am using version 1.2 (and also helped test it) as my main PBX system (810 extensions). It is quite stable and has some new and very useful features.
I will note however that occasionally if there is a problem with my internet connection or if a network cable is unexpectedly unplugged, Axon sometimes pops up an abnormal exception error. I usually just restart the application after that and everything seems fine. I don't know whether the program is able to accept calls during that time though.
The only other thing I might be concerned about for stability is if you intend on using VoIP phone lines, which in case you are not aware become completely useless in power failures and internet connection downtimes. In that respect, they are slightly more risky than traditional land-lines.
I personally use the Linksys Sipura 3000 (now 3102) FXO adapter to connect my analogue phone line and it works well. I had a few issues getting caller ID passed on to Axon, but have now solved this problem.
In terms of phones, the best ATA adapter I've used is also my Sipura 3000 (It works as both an FXO and FXS adapter). However I also have an Zxyel VoIP router that hasn't caused much trouble.
For phones, I recommend the Yealink [<a href="" rel="">http://yealink.com]</a> brand SIP and USB phones (NCH/Altoedge also sells their USB phone [[http://www.nch.com.au/hardware/usbphones.html]](http://www.nch.com.au/hardware/usbphones.html%5D)), however there is no problem with using regular analogue phones with an ATA adapter.
Recommended headsets: http://www.nch.com.au/hardware/headsets.html
For the server computer, I recommend:
- Windows XP (I wouldn't choose to use Vista, but that is up to you)
- Processor: 2.5 GHZ Pentium 4 or equivalent
- Memory: At least 512mb (I recommend 1 GB)
- 100mbit or 1gbit Ethernet connection to switch/router
In terms of realtime monitoring of calls in Queue, no such program exists (so far), however I imagine it would be possible to create a program that did so by reading Axon's logs.