For small- and medium-sized businesses, going all-VoIP is not an easy decision.

Fortunately, the switch-over, which can result in substantial savings and add bold new capabilities to tired old office phone systems, can be done in baby-steps: Purchase an Internet Protocol (IP) based phone system, but keep the PSTN lines, for now.

It is indeed possible to integrate VoIP into an existing office analog system, keeping current phone services intact while routing costly toll calls out over IP. Until recently, though, the hardware needed for such integration was difficult to use and expensive.

There are two ways to route calls between VoIP and the PSTN: subscribe to an Internet Telephony Service Provider (ITSP) or keep the PSTN lines and purchase equipment to make the conversion.

Keeping the PSTN lines requires VoIP gateways to convert the PSTN signal to a VoIP signal. For analog lines, these gateways need a Foreign Exchange Office (FXO) port.

Until recently, most reasonably priced VoIP gateways had only one or two FXO ports - enough ports for home use, but too few for small businesses and remote offices.

The average price for a four FXO port VoIP gateway was $400-$500, until Linksys released the SPA400.

The Linksys SPA400 is an attractive low-cost ($295) four FXO port solution that costs $100 less than its peers.

The official position from Linksys is that the SPA400 will only work with the Linksys SPA9000, but we’ve figured out how configure the SPA400 to work with other systems.

We share the the Open Source PBX Asterisk and the CommuniGate Pro Internet Communication System configurations at Voxilla.com.

The recent 2000-2005 FCC wireline (POTS) subscriber numbers are interesting - the number of POTS lines decreased. This in and of itself is not new and of much interest.

What is interesting is where the decrease happened - Kansas. The largest decrease (19%) happened in Kansas, a state not generally thought of as a technical leader. But, one should never underestimate the technical sophistication of the modern combine, most already have wireless 802.11 links back to the barn, VoIP is a logical next step for intra-farm communication.

The next largest decrease (13%) happened in New York. New York has a large mobile urban technophile population and so the numbers for that state are somewhat expected.

Michigan was also a surprise with the third largest decrease (12.5%). I’m originally from Michigan and still have a large number of relatives there; one generally wouldn’t put the state at the forefront of technology.

Illinois came in 8th with a 10.6% decrease. Chicago is a major urban area and the University of Illinois is a technological leader. I would have expected Illinois to rank higher.

Surprisingly, California did not make the top rakings. The only explanation I can think of is my own situation. That as people moved to California from other states, they left their landline in their old state and didn’t get a new one when they arrived. Thereby counting the decrease in the old state and not crediting California.

The future of POTS deserves watching and as technology advances Congress should reexamine whether spending Universal Service Funds (USF) on wireline solutions is the most cost effective use of tax dollars.