OptConnect devices themselves all come equipped with industry-standard security functionality, including their own subnets, firewalls, and access controls. Communications to connected customer equipment through OptConnect devices is minimized to only customer-specific needs (which again, only the customer has access to due to devices being on private networks).
Further, OptConnect device configurations and interfaces themselves are tightly locked down using a variety of best-practice security measures (such as multi-factor authentication, TLS, and asymmetric key cryptography), so OptConnect devices can only be accessed or changed by those inside the OptConnect organization.