Maybe old hat to you network engineers, but I was previously unfamiliar with "bits per second.kilometer".
Thanks for the info. No, this is not old hat to network engineers. I've never heard of it and I've been working in the industry for more years than I care to admit. I think it might be old hat to marketing people though, since it appears to be a classic BIG MARKETING NUMBER. Normal networking people would call 15.5 Tbps * 7000 km... 15.5 Tbps.
Maybe it's true that optics geeks really do use numbers this way, I dunno. But the fact it comes from an AlcaLu press release doesn't lend it a whole lot of credibility.
I am massively unimpressed by the headline on the Slashdot story. Maybe another article headlined "kdawson swallows inflated AlcaLu marketing fluff hook, line and sinker" would be in order?