AS6389 BELLSOUTH-NET-BLK

BELLSOUTH-NET-BLK is one of the largest consumer eyeball networks in the United States. Registered to AT&T Enterprises, LLC, it is the former BellSouth.net network — the internet arm of the BellSouth regional Bell operating company, absorbed by AT&T in 2006 and now the AT&T Southeast broadband footprint.

What it's used for

• Residential broadband across the old BellSouth nine-state territory in the US Southeast: DSL, U-verse and fibre subscribers.
• Small-business access riding the same access network.
• Announces on the order of four million IPv4 addresses — mostly full /16s such as 65.14.0.0/16, 74.228.0.0/16 and 74.238.0.0/16, aggregated into a few dozen large prefixes.

Notable

This is eyeball address space at national scale. A very large IPv4 count carried in a handful of big, contiguous blocks is the signature of a consumer access network: addresses are handed to household CPE from regional pools, so geolocation resolves to metro areas across the Southeast rather than to a single site. Traffic is evening-peaked and download-heavy.

Note carefully which AT&T entity this is: AT&T runs many autonomous systems, and AS6389 is specifically the BellSouth-inherited consumer network, not AT&T's global backbone or its mobility network.

Interesting

The AS number was registered in 1996, when BellSouth.net was standing up dial-up service — one of the RBOCs racing to sell internet access to their own telephone customers. The corporate name on the record has changed twice since; the routing has been continuous.