Installation Support AT&T Business Fiber (ABF)800.321.2000 AT&T Dedicated Internet (ADI) - with a customer provided router888.471.4574 ADI Support AT&T Virtual Private Network (AVPN) Plug and Play - with Plug and Play877.750.9305 AVPN Support AT&T IP Flexible Reach (IPFlex)888.528.8763 Disconnect in Error800.772.5383 5 more rows