AT-NET Services | 972 followers on LinkedIn. We provide Managed Technology Solutions for SMBs with a focus on CyberSecurity. | AT-NET is a managed technology services company headquartered in Charlotte, NC since 1999. A MSSP (Managed Security Service Provider) is what we are as a business to business company. If you are new to computer support done by an MSP, then you have come to a better level of service with AT-NET.