# Channel filter summary

MSPP channels consist of one or more channel filters, where each filter performs a specific processing task. The MSPP API supports the following channel filters:

Channel filter | Description
Jitter | Performs packet reordering and provides a buffering mechanism for smoothing jitter in packet media streams.
RTP switching | Acts as a pass-through filter to transfer data from one RTP IPv4 or IPv6 endpoint to another.
T.38 fax relay | Carries fax data between DS0 and T38UDP endpoints by performing fax data modulation and demodulation.
Voice decoder | Decodes and decompresses voice data. MSPP voice decoder filters include: G711 decoder: 64 kbps mu-law or A-law decoder G723.1 decoder: 6.4/5.3 kbit/s decoder G726 decoder: 32 kbit/s decoder G729A decoder: 8.0 kbit/s decoder
Voice encoder | Encodes and compresses voice data. MSPP voice encoder filters include: G711 encoder: 64 kbit/s mu-law or A-law encoder G723.1 encoder: 6.4/5.3 kbit/s encoder G726 encoder: 32 kbit/s encoder G729A encoder: 8.0 kbit/s encoder