The voice/fax modules enable packet voice technologies including voice over IP (VoIP), voice over Frame Relay (VoFR) and voice over ATM (VoATM). Cisco voice solutions provide the means for integrating both voice and data within a single network allowing users to take advantage of services, such as toll-bypass, without sacrificing voice quality.The Cisco High-Density Analog Voice and Fax Network Module provides DTMF detection, voice compression and decompression, call progress tone generation, voice activity detection (VAD), echo cancellation, and adaptive jitter buffering.