Chapter 3 Network Infrastructure Requirements
Audio Codecs
Table | Voice Message File Sizes and Audio Quality Ratings |
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Audio Codec |
| Approximate File Size, | Quality Rating | |
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G.711 | 480 KB | Excellent | ||
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G.726 | 32 Kbps |
| 240 KB | Fine |
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OKI ADPCM 8 kHz | 240 KB | Fine | ||
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OKI ADPCM 6 kHz | 180 KB | Fine | ||
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GSM 6.10 |
| 98 KB | Good | |
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G.729a |
| 60 KB | Good | |
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TTS, TTY, Pocket PCs, and Hand-Held Computers
For Cisco Unity sites using Text to Speech (TTS), any supported codec can be used to record messages. However, TTS output is currently available only in G.711 and G.729a audio formats.
For Cisco Unity sites using TTY, G.711 is required. The TTY standard does not support other codecs.
GSM 6.10 is supported for playback on a Pocket PC, and is a higher quality recording format than MP3. G.711 and G.729a usually are not compatible with
Interoperability Among Multiple Voice-Messaging Systems
If multiple Cisco Unity servers will communicate with one another via Cisco Unity Digital Networking or VPIM, or if Cisco Unity will communicate with other
Table
Networking Option | Supported Codecs |
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AMIS | The AMIS protocol is not dependent on audio format. |
| The Cisco Unity servers can use any of the supported codecs. |
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Cisco Unity Bridge | Octel Analog Networking is not dependent on audio format. |
| The Cisco Unity servers must use either G.711 or G.729a in order to |
| communicate with the Cisco Unity Bridge servers. |
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VPIM | For inbound messages, Cisco Unity can convert voice messages to any codec |
| that Cisco Unity supports. |
| For outbound voice messages, Cisco Unity can either convert voice messages |
| to G.726 format or not convert at all. Not converting is useful when you are |
| using VPIM to send voice messages between Cisco Unity servers. |
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Design Guide for Cisco Unity Release 5.x
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