Earlier quoted context omitted.
The problem is not just Comcast but everything of its ilk, and by that I mean Charter (Spectrum/former Time Warner Cable), RCN/Grande/Astound and similar giant size coax based DOCSIS3 operators. In Canada, Shaw and Rogers. They are absolutely determined to squeeze every last dollar of ROI out of that existing coax cable plant by doing asymmetric RF channels for downstream/upstream. And not overbuilding themselves wit…
I always thought the upstream speed was an artificial limitation so they could upsell "business internet" to people who wanted to host servers - and that they doubled down by reassigning your IP periodically if they saw a lot of incoming connections on layer 4. I did try hosting a server on my comcast cable internet for a while and the IP which I had for seven years prior did start changing every day - sometimes more…
I dunno about static vs dynamic ip. In ye olde days, there was a real capacity savings with dynamic, but I don't know very many people who don't have a 24/7 device leasing an IP anyway. It's certainly a way to get a little more revenue though.