!) It's the only ATA that supports google voice accounts, Pick the right OBI model though, the ITSP 30x series does not support google voice.
2) Extensions, The OBi is not a PBX if you want extensions you can setup freeswitch or asterisk on a micro computer raspberrypi, cubieboard, etc,. or an old linux desktop. The OBi could become used in multiple ways either as an entrance to your pbx, or as each extension (multiple obis)
A) You would have 1 OBi with the PBX controlling extensions, each person would then need a software client and headset to talk through their computer or cellphone or tablet
B) You can setup a PBX and each person could have their own OBi with phonejack and desk phone, which they could forward calls to and from the PBX
If you setup a PBX with one OBi and everyone in your office already has a cellphone you can ask them to install CSIPSimple the phone app and then setup an extension for each of them. Thus calls to the google voice will go to the obi and the obi will send them to the pbx which will ring the extensions, or the people can dial out using the google voice numbers from their extensions. They would all have to be on the work wifi and when they leave the premise it would no longer work unless you had a VPN or your PBX was public. You would all have extensions like 101, 102, 103, 104, and each could have their own voicemail. For what it is worth a good VoIP provider will offer this ability already, through subaccounts and multiple logins, transferring calls would be different for each but for the most part you could dial and merge and hangup, it would work the same. I use
VoIP.ms and I have subaccounts for laptop, tablet, phone, and OBi (wired into the phone jacks of the building), I have the automated menus and press 1 for ____, 2 for _____, and each have their own mailbox, that also sends copies of personal voicemail to their emails.
3) Have not tried it yet with a DoorBox, but which make/model do you want to use? The obi can send and receive calls to and from any number, you will need a SIP provider to send or receive sip calls since Google Voice is NOT a sip provider. You will need an OBi200 or OBi202 at the very least. If you go for an OBI 500 series that would give you 5 lines, and each person could have their own line/ext but you would have to dial their number to forward calls, if you have a sip provider the obi can bridge incoming calls and forward to and from SIP and it would be free calling sip to sip. Do you mean an apartment style intercom press 5 to release the door latch and let them in? or just an intercom? If you buy an OBi with a spare phone jack you can also run a direct burial wire to the doorand put rj11 phone jacks on both ends and use any phone as an intercom.
If i put a regular house phone mounted to a brick wall and sealed with silicone caulking, and program the OBi when PH2 (phonejack2), picks up wait 4 seconds then automatically dial the front desk. Then no one could ever dial anything else, the OBi's outbound call route would only ever allow calling the front desk and it would automatically call upon someone picking it up. (This is the ultra ghetto budget poor mans door intercom, but the neat thing is you can use sip to sip and have the OBi ring your cellphones extension for free, so you can know someone stopped by the office when you arent there too.) I was thinking of doing something like that since I physically can't hear the doorbell but always have a phone or other device near me. You can also do similar setup for seniors, alzheimers patients, stores, etc,. its just setup as a hotline phone that only allows one number to be called ever, I call them batman phones. Currently when i pickup my phone if i don't start dialing it automatically dials the balance info number of my voip provider.
Hopefully this sorta helped you, and you may get some more thorough advice from others, but in the mean time, I hope this helped. The OBi is an amazing device with lots of uses, it's not exactly a PBX so if you need extensions you need a sip provider that supports it, or you need to host your own locally with a pbx. That said if you program everyone elses numbers at the office into the obis and they have their own obi or they have an extensions from the pbx, you can easily just press
FLASH, XX# wait for the dial tone, FLASH (to merge calls), its now a 3 way call if you hangup it was successfully transferred. I have Lenny on speed dial 22, so I like to
FLASH, 22#, FLASH, MUTE + Speakerphone, and then listen silently as the poor telemarketers talk to Lenny.
Any how enjoy your weekend =P and good luck with your office setup, let us know how it goes =]
