These voice network modules and interface cards provide the means for integrating both voice and data within a single network allowing users to take advantage of services, such as IP telephony for enterprises or Voice over IP for Service Providers, without sacrificing voice quality. Cisco IOS® Software also incorporates built-in quality-of-service (QoS) features along with standards-based (FRF.11 and FRF.12) encapsulation and fragmentation, providing efficient direct transport of voice and fax over IP, Frame Relay, and ATM networks.