The forums are loaded with posts showing miserable wireless performance with that device !!! You may be better off calling in and having them put it in to bridge so that it acts as a plain vanilla cable modem and then use your own high quality wireless router with it.
I feel your pain! I was sold an "ugrade" to my Comcast package to save some money so I took it. I specifically asked the guy when he told me I was going to get a new modem was everything going to stay the same because I currently have WiFi in my house and want it to stay that way because I have laptops, iPhones & iPods and he said yes!
I received the new modem (arris tg862), installed it with some difficulty but got it up and running. Although now I can't seem to even connect to my email on the computer the modem is plugged in to but that's another topic.
My family & I were having problems connecting our iPhones and iPods back to the modem so I called Comcast. They proceeded to tell me that the internet connection was working so it was a problem with the WiFi so I'd have to be connected to Xfinity. Ok, fine whatever just get it working again.
I was put in touch with a woman and once again had to explain the situation and she told me that they could go in and fix the problem by setting up all new information in my computer which would allow up to 4 laptop computers and mobile devices to work with the new modem.....for a nominal one-time fee of $79.95. What???? Everything was working perfectly before so why isn't it now? She proceeds to continue on a synopis of the new modem and how they had to change the settings in the computer and in order to continue with the package once they updated my computer it would be an additional $9.95/month fee.
Are you seriously kidding me?
I have never felt so conned in my life and I am absolutely disappointed in the under handedness I feel Comcast.
Arris Interactive, L.L.C. TG862G is a piece of junk. Since receiving this thing, it looks good but it doesn't work. The Wifi drops constantly and I can't get on XBox Live anymore. My phone is always searching, my wife's Tablet is constantly doing the same thing. This will be the 5th call to get this thing working.