Ooma, Comcast, and frustration

On Oct. 15, a made a phone call to a friend who complained that my voice was “breaking up” and that he heard only every other syllable! Strange, his side of the conversation was very clear so I was puzzled why I “sounded so bad” to him.

I have had numerous conversations over the past nine days with Ooma and Comcast, each side blaming my problem on the other. I would hate to count the number of hours I have spent on the phone (Skype or cell phone) since my home phone system is virtually unusable.

I have a Motorola SB6121 modem, a Linksys E3200 with the setup Modem-Router-Ooma Telo, the same setup I have had for the past two years without any problem.

I have switched phones from cordless to corded, changed the configuration around placing Ooma in front of the router, ran all kinds of Pingnet tests and Speedtest, Ooma testing plus various other sites measuring speed, ping, packets, etc.

I had a Comcast service tech out to my home for nearly two hours, running line test, traceroute tests, ping tests, even to the point of running a direct line from their access hub in my yard directly to the modem in my home. Modem worked well but even tried a Comcast modem temporarily, no change in the line speed, upload and download except for a very few numbers-very consistent.

The “jitter’ number that I usually found to Chicago (the preferred testing site) was Ping:75ms, Jitter 89ms. However, if I change servers (to Sioux City, IA for example) the numbers changed to Ping 59ms, Jitter 3 ms. I know that Ooma prefers 5ms or less for optimum service.

My conversation with Ooma Level 3 tech support indicated that my latency was too high and Comcast needed to adjust it to something less than 100. Apparently my latency was averaging between 200-600.

I am frustrated with the entire process-thinking about other option. Of course Comcast offered the “triple-play” and there is always MagicJack’s new device for $35 per year or even the Straight Talk Home Phone setup for $15 per month.

I will praise both Ooma tech level 3 support and Comcast level 2 tech support for working very hard in an attempt to correct the problem but neither side has been able to resolve the situation.

Any suggestions-I am open to trying almost anything (except going back to a hardwired phone company landline!)

When you put in a different modem, did you notice any difference? (test to see if other side can hear you okay?)
If new modem doesn’t fix the issue (I am guessing big issues with upload side of things as far as dropped packets, jitter, latency), try and have Tom B take a look at your carrier routing https://www.ooma.com/forums/memberlist.php?mode=email&u=4164

It was a Comcast problem. After a great deal of testing by Comcast techs, it was determined that I had been switched to a different node. While I am not sure what that means, it was fixed by Comcast and everything is back to normal.

I’m having the exact same issue that you experienced and am also a Comcast subscriber. When I’m on the phone the other party stops hearing me completely, my voice becomes garbled or the call abruptly drops.

I just spoke to OOMA customer support this morning and they did some testing. They mentioned the “jitter” issue and blamed it on Comcast. How exactly did you get Comcast to troubleshoot and resolve the issue? I plan on calling Comcast next, but it would be helpful if I could tell them specifically what to resolve or check.


If you have a newer comcast issued router/modem combo, put your Ooma in DMZ.

thanks for the awesome information.