Codecs (Coder/Decoder) serve to encode voice/video data for transmission across IP networks. The compression capability of a codec facilitates saving network bandwidth and it is therefore appropriate that you choose the correct codec for your IP network. Here is a quick reference to the codecs with the corresponding packets size and bandwidth usage:
| Codec & Bit Rate (Kbps) | Operation Frequency | Default number of packets | Voice Payload Size | Bandwidth MP or FRF.12 (Kbps) | Bandwidth w/cRTP MP or FRF.12 (Kbps) | Bandwidth Ethernet (Kbps) |
|---|---|---|---|---|---|---|
| G.711a/u (64 Kbps) | 60 msecs by default. You can specify in the range of 0 - 604800 msecs. | 1000 | 160 + 12 RTP bytes | 82.8 Kbps | 67.6 | 87.2 |
| G.729 (8 Kbps) | 60 msecs by default. You can specify in the range of 0 - 604800 msecs. | 1000 | 20 + 12 RTP bytes | 26.8 Kbps | 11.6 | 31.2 |