Buffering Issues

Hello All,

I've been a customer for many many years mainly cause the cities I move to don't offer anything else.  I've been having this ongoing issue now for the longest time and it's really infuriating.  We're on the 1GB internet speed.  I subscribe to an IPTV service which if anyone know is Internet Protocol TV.  With that being said it was buffering when using it, I then figured it was the service so I tried another one, same thing.  It'll play a movie or tv show and then it'll say playback error and restart the stream, or just completely buffer.

I did make a change recently to the DNS servers that Comcast uses to Google's but it doesn't matter what I do, I just get buffering.

Anyone have any suggestions?  Is there a way to check for any firmware updates on the modem I am using with Comcast?  Am I better off getting my own?

I am running out of ideas here.

Thank You