Having problems with keeping your OOMA phone system connected? Before you blame OOMA, the problem could lie with your ISP. Fortunately, the fix is relatively easy.

[caption id="attachment_127" align="alignright" width="300" caption="OOMA Hub and scout"][/caption]

The OOMA hub and scout units have a tab indicator that show at a glance when the device is working correctly. A blue tab indicates that the box is working and has a good internet connection.  A red  tab indicates there is no internet connection (and you cannot make or receive phone calls through the OOMA).

After about a month using the OOMA, I began to notice OOMA connectivity issues that I thought might indicate a problem with the unit. I have about a half dozen always-on devices running on the network. So when OOMA started showing no internet connection but everything else (most but not all of the time) seemed to be humming along just fine I blamed the OOMA. After one frustrating saturday evening when the OOMA connection would not stay connected for more than about 30 minutes at a time, I turned to my firewall logs to try and determine what exactly was going on. .

The logs showed that a lot of DNS requests (UDP port 53) were failing or taking a really long time (latency) to complete. Compared to the Popcorn hour media center, the XBOX, TIVO and other network connected devices, the OOMA was sensitive to DNS errors and was making a lot (comparatively) of external requests. Each request to the OOMA server would first go to the ISP's DNS server to resolve the name into an IP address and when that request was not resolved in a timely fashion, OOMA would apparently think that the internet connectivity was lost and the tab would turn red and . Meanwhile, other devices on the network would not notice anything or would perhaps slow down but not indicate any connectivity issues.

Once I figured this out, I looked at my network configuration and made some changes. As I said, I have my own firewall behind the Verizon DSL modem (Westell 6100), which can also act as a firewall. When I first setup the Verizon DSL I had turned off all of its firewall features so that it would not filter or block any services that my firewall had already permitted. I did let the Westell unit assign the IP address and DNS server to use to my firewall (which in turn propagates that DNS server to the LAN).
The solution to fix the problem was relatively easy, instead of using the default Verizon DNS settings I assigned my own DNS server, using the OpenDNS service. I had used OpenDNS on individual computers on the LAN in the past but had not made it the default choice at the firewall. I made the change, restarted the Westell DSL modem as well as the firewall and my wireless router (I wanted to ensure that everything came up fresh). It was like I had just received a brand new OOMA unit! Instead of seeing that red tab show up anywhere from one to five or six times a day I rarely see it anymore and when I do it usually corrects itself before I can get over to the box to take a look.

So, if you are having performance issues with your OOMA try changing your DNS server I recommend OpenDNS as a free and very stable choice.