Observed topology

AS20340 CALLTOWER - CallTower, Inc.

Hosting ARIN Content

Upstreams 22 carry this network

Downstreams 1 this network carries

Adjacent (IPv4) 23

Adjacent (IPv6) 0

Upstream graph Who carries AS20340, and who carries them, drawn as a map up to the transit-free core. 7 exchanges Where AS20340 physically turns up to peer, and its address on each fabric.

Transit

Upstream networks

All 22

Networks observed carrying traffic for AS20340: the AS immediately before it in a routing path. Ranked by how many paths showed the relationship, which reflects how widely it is used, not how much traffic crosses it.

AS	Network	Type	Families	Paths seen
AS6939	Hurricane Electric LLC	Transit	IPv4	622
AS8220	COLT Technology Services Group Limited	Hosting	IPv4	136
AS16260	EMEA Ltd.	Unclassified	IPv4	75
AS174	Cogent Communications, LLC	Transit	IPv4	73
AS19855	Masergy Communications, Inc.	Unclassified	IPv4	58
AS3356	Level 3 Parent, LLC	Transit	IPv4	48
AS7018	AT&T Enterprises, LLC	Residential	IPv4	46
AS3257	GTT Communications Inc.	Transit	IPv4	38
AS13768	Aptum Technologies	Hosting	IPv4	36
AS24482	SG.GS	Hosting	IPv4	14

All 22 upstreams →

Transit

Downstream networks

inferred

Networks for which AS20340 was observed as the last hop before the origin, meaning it appears to provide them transit.

AS	Network	Type	Families	Paths seen
AS46168	CallTower, Inc.	Unclassified	IPv4	59

Adjacency

Adjacent networks

All 23

Every AS seen directly next to AS20340 in a routing path, in either direction.

AS	Network	Type	Families	Paths seen
AS6939	Hurricane Electric LLC	Transit	IPv4	622
AS8220	COLT Technology Services Group Limited	Hosting	IPv4	136
AS3257	GTT Communications Inc.	Transit	IPv4	97
AS16260	EMEA Ltd.	Unclassified	IPv4	75
AS174	Cogent Communications, LLC	Transit	IPv4	73
AS46168	CallTower, Inc.	Unclassified	IPv4	59
AS19855	Masergy Communications, Inc.	Unclassified	IPv4	58
AS3356	Level 3 Parent, LLC	Transit	IPv4	48
AS7018	AT&T Enterprises, LLC	Residential	IPv4	46
AS13768	Aptum Technologies	Hosting	IPv4	36

All 23 adjacent →

Provenance

Where this comes from

Derived from routing tables collected at 2026-11-11 10:00 UTC by route-views2,rrc00, as seen from 74 BGP vantage points across 73.24M route entries. These are observations from those vantage points, not a complete or authoritative view of the internet.

Inferred from path position, not from any declaration by either party. A network appearing here is carrying these routes; whether that is a paid transit arrangement, a backup, or something else is not something routing data can tell you. Adjacency is not the same as peering. Being next to each other in a path covers paid transit, settlement-free peering and customer connections alike, and routing data cannot distinguish them. Treat this as "these networks exchange routes", nothing more specific.

Cross-check against RIPEstat or BGP.tools, which observe from a different and larger set of vantage points.