[VoIP] Traditional PBX or VoIP Based?

[David Josephson]

Only one main thing to add to what Dennis, John etc. have written. That 
is, it depends on *who* will be doing the planning, install and support. 
Find out who that will likely be, and what system they consider the most 
reliable.

Yes, Asterisk is great, but there is no standard of installation 
competence and support that makes it work if you are gone. Some friends 
have deployed Asterisk in their companies (using Cisco 7940 and 7960 
phones, not the Linksys-origin ones) and they are happy -- but they are 
Unix geeks and any one of them can fix things in fairly short order. 
This applies to all the "legacy" systems too -- the key will be, who in 
your local community has the chops to support the system? There are good 
systems from Avaya (nee Lucent, nee AT&T, Bell Labs origin), NEC, 
Panasonic, Toshiba, Vodavi and others. I gather it's not a big system. 
The key is having it be just capable enough to do what the folks want it 
to do -- but not overwhelm them with features that will confuse them. 
FIgure out who you would send the RFQ to, and ask them -- what systems 
do you sell, what systems do your techs like working on most, on which 
systems will you release programming manuals and training to the end 
user technician so he (you) can make moves/adds/changes yourself? Beware 
of the latest and greatest. My choice would be Avaya Magix (or Legend, 
if they will accept refurb/NOS equipment) or Toshiba. But it really 
depends on what system has the best local support.

Using an internet telephony provider is a real non-starter, unless you 
happen to have a secure circuit to the point where the telco hands off 
to the VOIP box. Even business-grade IP connectivity is not reliable 
enough for public safety uses, unless you have dedicated and redundant 
circuits to a well-engineered peering point.

Where you can help the most is by analyzing the reliability of each 
proposed system -- how many single things can fail and take it down? Is 
there a backup or workaround? What's the mean time to repair?

We went through a similar exercise a year or so ago at my shop here. We 
have up to 8 people working here, about a dozen extensions. I wanted 
something cheap but solid. It needed voicemail and caller ID, but 
nothing more fancy than that. I learned about the Avaya Legend stuff by 
downloading all the manuals and buying pieces on eBay. I think we spent 
a total of $800 or so for two dozen display stations, a T1 trunk (for 
interface to Asterisk), some 2-wire analog extensions and caller-ID 
trunks, voicemail, spare processors, etc.

--
David Josephson