Bandwidth is the underlying carrier or tandem provider (path that a call routes down) for a portion of nearly all VOIP carrier's traffic. Google Voice & Microsoft Teams Voice & Conferencing entirely rely on Bandwidth.com for calling & texting.

In many ratecenters, your only choices are buying tandem transport for incoming calls from Onvoy, Bandwidth.com, Peerless Networks, West/Intrado/Flowroute or establishing your own physical presence to switch calls and paying the incumbent telco for connectivity.