The National Advertising Division (NAD) has sided against AT&T following a complaint brought over certain Cox Communications marketing materials.

The complaint centered around a 30-second television spot that claimed Cox offered “unbeatable 5G reliability” with respect to its wireless service sold under the Cox Mobile brand. The claim was related to Verizon’s network as measured by RootMetrics. Verizon provides the network technology used by Cox for its mobile services.

In a statement, Cox said it “appreciates the NAD’s recognition that its unbeatable 5G reliability claim is fully supported.”

It wasn’t clear if AT&T plans to appeal the decision to the full National Advertising Review Board (NARB), which provides an additional layer of scrutiny to NAD decisions.

Cox Mobile continues to use the “unbeatable 5G reliability” claim on its website.