I’d like to post the entire contents, but I’d recommend everyone to go over to the Fonality web site and sign up to receive their whitepaper VoIP without Hype – What Busnesses Need to Know which contains a rather dispassionate discussion of the role of VoIP in the context of our “traditional” phone system. Of several migration approaches discussed, the most conservative, yet still effective is the “hybrid PBX”, using IP phones inside the business, and connecting calls over the internet between branch offices, but retaining the ability to still make calls over the regular telephone network.

Whatever approach you decide on for migrating to
VoIP, a hybrid IP-PBX is an excellent first step. Hybrids
operate in three modes – PSTN, VoIP, and what’s called
PSTN-fallback – a mode which ensures that you’ll
always have phone service, even during Internet
outages. With a hybrid IP-PBX, you can also connect
and use analog phones (including cordless sets), IP
phones, or a combination. So you can convert select
employees to IP telephony according to their needs
and the capacity of your Internet connections.

A hybrid IP-PBX enables you to start saving money right
away, even if you choose to use the PSTN connections
to the outside world. With a hybrid IP-PBX at your
business, you get free VoIP calls between offices and
with all your telecommuters, but you can selectively
choose to pay more for calls across the PSTN where
the quality matters most. Think of it this way, your
employees get free VoIP calling between themselves,
but your customers are guaranteed perfect POTS
quality when they call you, or you call them.

Fonality is the vendor which snapped up the very wonderful TrixBox. So, the whitepaper is more useful than many, as it points out the disadvantages of VoIP, and it doesn’t promise the moon.