The gateway voice codec system for the Analog Devices ADSP-21mod9XX family of DSPs is designed to meet or exceed the requirements for H.323/H.324/MGCP/SIP. This system supports multiple channels of up to 32 ports in the ADSP-21mod980 (4 simultaneous channels on each DSP) configured in an arbitrary mixture up to the available MIPS of each processor. Standard features include G.711, G.723.1/A, G.729A/B, G.165 Line Echo Canceller with an adjustable tail length of up to 32 msec, DTMF generation/detection, voice/fax/modem discrimination and echo cancellation disable (2100 Hz). Optional features include T.38, G.721/G.726, G.728, G.729, G.729D, G.729E, GSM Full Rate, GSM Half Rate, GSM Enhanced Full Rate, GSM Adaptive Multi-Rate and G.168 Line Echo Canceller with variable tail length of up to 64 msec.