24 lines. As ISPs got bigger/more efficient, they moved to T-3/DS3 lines (672 lines per). I can only think of a handful of ISPs that went bigger than that. B

24 lines. As ISPs got bigger/more efficient, they moved to T-3/DS3 lines (672 lines per). I can only think of a handful of ISPs that went bigger than that. By the time OC-3 and larger channels became cost effective, the era of dial-up was pretty much over.