AS11623 CTCN

CTCN is CT Communications Network — the internet arm of CT Comm of Urbana, Ohio, the local telephone company for Champaign County, which traces its origins to the Champaign County Telephone Company. It is a small independent ILEC selling internet, phone and TV in its home territory.

What it's used for

Last-mile broadband and the operator's own backbone. The reverse DNS names the access technology directly and is the clearest evidence in the pack: 65-75-224-5.dsl.ctcn.net and 67-43-200-5.dsl.ctcn.net are DSL subscriber addresses; 67-43-192-5.backbone.ctcn.net is the operator's own core; and 65-75-232-5.unused.ctcn.net is a block the operator has explicitly labelled as unassigned. A provider that tags its own pools dsl, backbone and unused in its own domain is running an access network on its own space, and there is no ambiguity about what the addresses carry.

Notable

RIS sees 3 announced v4 prefixes carrying 8,192 addresses, one IPv6 prefix (2607:8540::/32), and one observed BGP neighbour. The single upstream is the role signal: this is a customer edge that buys transit, not a carrier. All three v4 prefixes — 65.75.224.0/20, 67.43.192.0/20 and a /24 carved from the latter — are registered to CTCNETWORK (org: CT Communications Network), so the space is entirely self-held.

Interesting

The /32 of IPv6 is an ISP-sized allocation, sized for delegating prefixes to subscribers, and it is announced — a small rural telco with production v6 while much larger networks in this sweep announce none at all.

The name invites a wrong guess: CTCN and "CT Communications" read as Connecticut. The address record puts it in Ohio.