I have an OBi-100 using my Google Voice account over my AT&T DSL and it works flawlessly. I can't even tell it's not a landline. I was considering switching my ISP to Comcast cable, and a friend told me VOIP won't work as well on Comcast due to jitter. Can any Comcast users confirm or deny this? Thanks!
I have both an OBi100 and an OBi110 with Comcast Cable without any problems.
I have 3 Obi's myself and also one at my sister's and one at my niece's, all on Comcast without a problem.
When my niece dropped her comcast digital voice for the Obi and google voice, she commented on how much better the call quality was.
Comcast HSI subscriber and I've been using an Obi110 for over a year now with no issues. Less issues than the T-Mobile @Home service I ran in parallel until last night when I finished porting the number to Google.
I had Comcast for years (in two different states) running into a Vonage box. Unless you have something funky in your neighborhood Comast will provide you a nice solid data stream. The bandwidth required for a voice channel is nothing compared with the requirements for streaming video, but if you are using a router in between the Obi box and the modem you want to make sure you have the QOS setup properly so that Obi gets priority. How exactly you go about doing that depends on your router.