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Configuring and Managing the High-Density Packet Voice Feature Card
Configuring the GSMAMR-NB Codec for the High-Density Packet VFC
75
Cisco VGD 1T3 Voice Gateway Software Configuration Guide
Configuring the GSMAMR-NB Codec for the High-Density
Packet VFC
This section provides information about the following:
•
Overview and Restrictions for the GSMAMR-NB Codec, page 75
•
GSMAMR-NB Codec Compliance with RFC 3267, page 76
•
Configuring the GSMAMR-NB Codec on the High-Density Packet VFC, page 77
Overview and Restrictions for the GSMAMR-NB Codec
The Adaptive Multirate Narrow Band (AMR-NB) codec is a high complexity multimode codec that
supports eight narrowband speech encoding modes with bit rates between 4.75 and 12.2 kbps. The
sampling frequency used in AMR-NB is 8000 Hz and the speech encoding is performed on 20 ms speech
frames. Therefore, each encoded AMR-NB speech frame represents 160 samples of the original speech.
The AMR-NB codec was originally developed and standardized by the European Telecommunications
Standards Institute (ETSI) for Groupe Speciale Mobile (GSM) cellular systems. and chosen by the Third
Generation Partnership Project (3GPP) as the mandatory codec for third generation (3G) cellular
systems.
Note
You must buy a license to access the DSPware that supports the AMR-NB codec. It is recommended that
you purchase a Cisco SMARTnet contract in order to streamline the process of getting the AMR-NB
codec DSPware. When obtaining your license, use the following part numbers:
•
FRVGD-AMR-LIC for the Cisco VGD 1T3
•
FRVGD-AMR-LIC for the Cisco VGD 1T3
For more information, contact your Cisco representative or visit the following Cisco.com website to
obtain a Cisco SMARTnet contract:
http://www.cisco.com/en/US/partner/products/svcs/ps3034/ps2827/ps2978/serv_datasheet09186a0080
092491.html.
Table 1
contains codec mode and bit rate information for the AMR codec.
Step 5
exit
Example:
Router(config-voicedsp)# exit
Exits config-voicedsp configuration mode and returns to
global configuration mode.
Step 6
end
Example:
Router(config)# end
Exits global configuration mode and returns to privileged
EXEC mode.
Command or Action
Purpose