According to John via the RTC mailing list:
Suddenlink finally traced the problem to an interface processor card on a router in San Jose that connects their North Coast region to the rest of the Suddenlink backbone. They announced the resolution to us yesterday and our own testing last night confirmed that the problem is solved.
This is good news for those of us still using Suddenlink for Internet access. Now what are they going to do about the cable glitches? Was I the only one who had most of Tuesday night’s episode of ’24’ garbled? I mean, talk about torture!