Cisco AS5800 Voice Feature Cards are full-featured voice processing cards that support Voice Activity Detection (VAD), comfort noise generation, adaptive jitter buffering, programmable 16 and 32-msec echo cancellation, programmable frame size, and Dual Tone Multiple Frequency (DTMF) detection and generation. Medium-complexity Cisco AS5800 Voice Feature Cards offer an industry-leading DSP density and support for MC VoIP codecs, including G.711, G.729a, G.726, and T.38 with Group III real-time fax support, on any port at any time.