Google Voice , Obi202, Obi200, e911, and Faxing

I have held off for some time at getting an Obi200 which is the only "official" adapter for Google Voice. There are some web posts that tell one how to set up your asterisk (or other PBX, or IP Phone) for use with Google Voice through the Obi.  Yes asterisk still can be used directly without the Obi  but the instructions are not clear and relying on the community to get help does not work so well. It seems many elude to the "violation of TOS" meanwhile they themselves use it. Also any change on the part of Google could render such an asterisk configuration unusable as we have seen before. 

Recently I made the purchase of an Obi202, as the prices of the Obi200 had soared from $39.00 to just over $50 dollars now. I was able to find a New Obi202 on ebay with the "Make Offer" option. In the end, I figure I got a free second port on the Obi202 for the same price as the Obi200. 

The main difference in the Obi200 vs Obi202 is the number of phone ports and service providers that one can configure. The Obi202 has two phone ports while the Obi200 has just one. Recently I had purchaed a used Multi-function device that includes fax capabilities. That meant that suddenly, I found a new use for that second port, although in reality I may have been able to configure an Obi200 with the same services.  I now use , two Google Voice accounts and one account for asterisk.  One Google Voice number is for Voice and the other is for Fax. The asterisk account allows me to use any existing IP phones I already have with Google Voice. The Fax connects directly to the second phone port on the Obi. The First Phone port on the Obi is unused. 

For the last year or so, I have been running only text based asterisk on a Raspberry Pi3, previously I had run a Grandstream HT503 connected to a copper phone line. Now that I have returned to the USA I have gone pure VoIP, and as I have used the Google Voice number for years already, it seemed logical to use the free Google Voice service for my USA calling and faxing needs.

The initial setup of the Obi202 was super simple using the Obitalk portal, that is while using only two Google Accounts. Incorporating the asterisk was a little more complex. 

For 911 service I used GV911.com . It is $12.00 per year, per line and easy to implement from asterisk too. This is the only recurring coost in this set-up even if I make and receive calls all day.

At first I had some issues with Faxes and lowered the speed down to 14.4kbps on the fax machine. Later I found some settings in the Obi . Five of these settings seemed key in allowing me to set the Fax speed to 33.6kbps. 

Physical Interfaces > Phone 2 (or 1) settings

1 Disable call waiting (Checked)

2 Use for Fax Only (checked if using dedicated fax only)

3 Fax Detection Method (CNG or CED)

4 Detect Phone CED Phase Reversal (Checked)

5 Detect Network CED Phase reversal (Checked) 

As far as I can tell so far, I now have reliable Fax in and out at 33.6kbps on a free dedicaed Fax line .

The voice quality is also quite good and I can use all of my asterisk features like Spam call filters, and the like. I can choose to use asterisk voice mail or Google Voice voicemail. 

The $50 was money well spent and the Google Voice service is worth that, especially given how well it integrates to my existing asterisk with SIP protocol.