AT&T, Hughes and Verizon retain the top three spots on the latest Vertical Systems Group software-defined wide area networking (SD-WAN) rankings for year-end 2019.

Vertical Systems Group’s Carrier Managed SD-WAN Services Leaderboard lists AT&T atop its peers for number of managed SD-WAN customer sites in the U.S. at the end of last year. AT&T has been partnering with VeloCloud since 2016 for its platform.

CenturyLink advanced to fourth position, which dropped Windstream from fourth to fifth position. Aryaka ranks sixth and Comcast moved up to seventh position from eighth on the 2018 leaderboard. Fusion Connect dropped off the leaderboard into the challenge tier for 2019.

These seven service providers each had 2% or more of installed and billable carrier managed SD-WAN customer sites in the United States.

“The U.S. managed SD-WAN market expanded rapidly in 2019 as backlogged orders from the prior year were fulfilled by key service providers,” said Rick Malone, principal of Vertical Systems Group. “While the duration and depth of the coronavirus economic collapse is unknown, we expect resiliency across bandwidth-intensive VPN markets, but acute vulnerability for the SD-WAN networks supporting the retail and travel verticals.”

In addition to Fusion, GTT, Masergy, Meriplex and TPx are in the challenge tier. It includes service providers with between 1% and 2% share of U.S. carrier managed SD-WAN sites.

Billable U.S. installations of carrier managed SD-WAN services increased 89% last year. Large businesses and enterprises increasingly rely on service providers to help configure, implement and manage their SD-WAN deployments.

Bigleaf and Sprint, which were both cited in the 2018 challenge tier, dropped into the 2019 market player tier.

Comcast is the only service provider on the leaderboard that has attained MEF 3.0 SD-WAN Services certification. This market differentiator assures compliance with the MEF 70 global standard for SD-WAN managed services.

Five leading technologies enable the SD-WAN services offered by the leaderboard and challenge providers – VMware by VeloCloud, Cisco vEdge (Viptela), Cisco Meraki MX, Fortinet and Versa. Additionally, several SD-WAN providers utilize their own internally developed technologies.

Versa is the only one of these suppliers that has achieved MEF 3.0 SD-WAN Technology certification to date.

In addition to Bigleaf and Sprint, market players include such providers as AireSpring, Cogent, Colt, Frontier Communications, MetTel and NTT.

The study does not count do-it-your-self solutions bought directly from the supplier or partner.