A Scientific Atlanta digital cable box with iO TV service is required for all features. Web DVR requires DVR for iO TV and Optimum Online. DVR service requires digital cable box with DVR capabilities. An active Optimum Online ID and password is required for online DVR management. Caller ID on iO TV is only available to customers with all three Optimum services (iO TV, Optimum Online and Optimum Voice). The Caller ID on iO TV function will not distinguish between multiple lines.