The voice connection and management is independent of the data setup. In fact, with VoDSL the subscriber receives dial tone whether or not the IP data service is active or properly configured. The data and voice OSS as well as personnel can continue to be leveraged with the linkage between the two occurring as a protocol interface between the back-office management systems and the gateway management system. Service Assurance Service creation is just the beginning of a successful VoDSL deployment. After creation comes assurance.
Subscribers have an unyielding expectation that going off hook on a phone provides dial tone.
The voice network is incredibly reliable in this sense. But the data network is dynamic, which requires a higher level of policing to ensure services are delivered appropriately with their intended quality. ATM networks, which were designed from the beginning to deal with such issues, are ideally suited for mixed voice and data traffic. Such events include the loss of communication with an IAD due to a failure as well as network performance issues like jitter, latency and bandwidth availability to deliver the SLA promised the subscriber. In effect, the IAD becomes another network element with northbound alarm generation capabilities.