Tier 1 backbone · AS3356 · United States
SUN · 26 JUL 2026
Lumen Technologies (Level 3)
About this network
Lumen operates AS3356, the largest IP backbone by autonomous-system relationships on the public internet. The network was assembled through a string of mergers (Level 3 acquired Global Crossing in 2011; CenturyLink acquired Level 3 in 2017; the combined entity rebranded as Lumen in 2020). It is a default Tier 1.
Notable
Largest Tier 1 by peer count. Operates the largest IP backbone by AS-relationships globally.