VoIP Settings
7-8
7
Codecs
A codec (coder/decoder) is the way a voice analog signal is converted into a digital
bitstream to send over the network, and how it is converted back into an analog
signal at the receiving end. Codecs differ in the type of data compression that is
used to save network bandwidth and in the time delay caused in the signal. This
results in different voice quality experienced by the user.
The voice codecs in common use today have been standardized by the International
Telecommunication Union Telecommunication Standardization Sector (ITU-T) and
are identified by a standard number, such as G.711 or G.726. The same codec must
be supported at each end of a VoIP call to be able to encode and decode the signal.
Since devices in other networks may want to use different codecs, the OD200
provides support for several common standards.
Figure 7-5 Codecs
Codec
– Lists the codecs supported by the OD200. You can enable specific codecs
to use, or enable all. Alternatively, you may want to disable certain codecs, such as
high-bandwidth codecs, to preserve network bandwidth.
•
PCMA (G711.aLaw):
The ITU-T G.711 with A-law standard codec that uses Pulse
Code Modulation (PCM) to produce a 64 Kbps high-quality voice data stream. This
standard is used in Europe and most other countries around the world.
•
PCMU (G711.uLaw):
The ITU-T G.711 with mu-law standard codec that uses
Pulse Code Modulation (PCM) to produce a 64 Kbps high-quality voice data
stream. This standard is used in North America and Japan.
•
G723:
The ITU-T G.723 standard codec that uses Adaptive Differential Pulse Code
Modulation (ADPCM) to produce data streams of 24 and 40 Kbps. This standard
has now been superceded by G.726.
•
G729ab:
The ITU-T G.729ab standard codec that uses Conjugate Structure
Algebraic-Code Excited Linear Prediction (CS-ACELP) with silence suppression to
Summary of Contents for Edge-Core OD200
Page 1: ...Powered by Accton www edge core com User Guide OD200 Outdoor WiMAX Residential Gateway...
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Page 12: ...viii Table of Contents Glossary Index...
Page 16: ...Figures xii...
Page 26: ...Introduction 1 10 1...
Page 36: ...2 10 Installing the OD200 2...
Page 58: ...System Settings 4 10 4...
Page 98: ...Wi Fi Settings 8 10 8...
Page 108: ...Cables and Pinouts C 4 C...
Page 118: ...Glossary Glossary 4...
Page 122: ...Index 4 Index...
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