A codec is a software algorithm used to compress/decompress speech or audio signals in Voice-over-IP (VoIP) networks.
Use this procedure to add a codec option to a voice class codec in a region.
You must be in the Design View to add a codec to a voice class codec.
Expand the dial plan tree to view all components.
Locate the region which contains the voice class codec you want to add a codec to.
Click the Voice Class Codecs tab.
Double-click the voice class codec you want to add a codec to.
Click the Codecs tab.
Right-click and choose Add from the menu.
Enter the attribute information:
Name - Sets the codec options that you can use when you execute this command. See the following table for a list of codec options.
Note: Not all codecs are available on all gateway platforms. Check the Cisco IOS version on your gateway to see which codecs are supported.
Codec Option |
Description |
g711alaw |
G.711 a-Law at 64,000 bits per second (bps) |
g711ulaw |
G.711 u-Law at 64,000 bps |
g723ar53 |
G.723.1 Annex A at 5300 bps |
g723ar63 |
G.723.1 Annex A at 6300 bps |
g723r53 |
G.723.1 at 5300 bps |
g723r63 |
G.723.1 at 6300 bps |
g726r16 |
G.726 at 16,000 bps |
g726r24 |
G.726 at 24,000 bps |
g726r32 |
G.726 at 32,000 bps |
g728 |
G.728 at 16,000 bps |
g729br8 |
G.729 Annex A and B at 8000 bps |
g729r8 |
G729 Annex A at 8000 bps |
gsmcfr |
12200 bps |
gsmfr |
13200 bps |
transparent |
Transparently pass capabilities between endpoints. Note: When you specify a transparent codec it must be the preference 1 codec. |
Preference - Specifies the order of preference for this codec. The range is 1 to 14, with 1 being the most preferred and 14 being the least preferred.
Bytes - Specifies the number of bytes in the voice payload of each frame. The range is 10 to 240.
8. Click Apply. The codec is added.
Click Cancel to cancel this procedure.