Advantage using OBi504vs vs. Two OBi202?

[SteveInWA]

It's interesting to see that so many people have good input on this topic.

For some "out of the [Obi] box" thinking (sorry, I just couldn't resist):  forget about Google Voice.  The limitation Robert described is one reason to consider an alternative:  Buy each kid a OBi 200, with the advantage previously mentioned that it becomes "their" telephony device that can be moved or changed with ease.  Attach a DECT 6.0 cordless phone to each one -- I think DECT is sufficiently robust to support multiple base station radios in one building.  This eliminates any wiring issues.  Provision each OBi with a SIP ITSP DID (inbound phone number) and a calling plan, from a good service provider like Callcentric or voip.ms.  Eventually, the kids can contribute towards, or fully pay for their phone service.  If "parental oversight" is desired, you'll have a detailed call log for each user.  The numbers will be easily portable, they'll support E911 emergency calling, and they'll have all the features of modern phone service, like call waiting, call forwarding, caller ID with name, 3-way calling, voicemail, etc.

[Mister_M]

Buy each kid a OBi 200, with the advantage previously mentioned that it becomes "their" telephony device that can be moved or changed with ease.  Attach a DECT 6.0 cordless phone to each one -- I think DECT is sufficiently robust to support multiple base station radios in one building.  This eliminates any wiring issues.  Provision each OBi with a SIP ITSP DID (inbound phone number) and a calling plan, from a good service provider like Callcentric or voip.ms.  Eventually, the kids can contribute towards, or fully pay for their phone service.  If "parental oversight" is desired, you'll have a detailed call log for each user.  The numbers will be easily portable, they'll support E911 emergency calling, and they'll have all the features of modern phone service, like call waiting, call forwarding, caller ID with name, 3-way calling, voicemail, etc.

Although this would be the simplest solution, the initial setup cost would be twice as much as what I was looking at for hardware plus a monthly charge for service from CC or voip.ms.  We already have E911 on our current line, so I think it would be redundant to provide it on each line.  The above doesn't seem to be much different than just getting them a cell phone on a family plan.

[SteveInWA]

There's going to be an initial cost to any solution.  You need some sort of telephone, and some sort of telephone service.  Google Voice isn't a free phone company -- you still need a DID to assign to each GV account.   You now have enough information about all the alternatives to decide how much you want to pay for a VoIP vs. cell phone solution.

[Mister_M]

You bet.  Thanks all for the input.