[asterisk-users] Are the Siren7 and Siren14 the G.722 HD voice codecs?

[Steve Underwood]

On 01/05/2011 03:29 PM, Bruce B wrote:
> Hi Everyone,
>
> 1- Are the Siren7 and Siren14 the G.722 HD voice codecs?
> 2- Are these codecs only for Polycom units or are they universal 
> across all other SIP phones that advertise the HD voice codec like Aastra?
> 3- What is the main difference between the two and is it advisable to 
> run these over the INTERnet (not INTRAnet)?
>
The G.722 codec in * is G.722. The Siren7 codec in * is probably not 
Siren 7, but G.722.1. G.722.1 is very similar to Siren7, but uses a 
different code in the SDP and has some minor differences in the codec. 
The name G.722.1 may look similar to G.722, but the codecs bear no 
relation to each other. The Siren14 codec in * is probably not Siren14, 
but G.722.1C. G.722.1C is very similar to Siren14, but like 
Siren7/G.722.1 the SDP code is different, and there are minor 
differences in the codec.

G.722.1 is a 7kHz bandwidth codec. G.722.1C is a stretched version 
offering 14kHz bandwidth. These are most often found in Polycom phones, 
but they are available elsewhere. The only widely supported HD codec is 
G.722. Pretty much anything offering wideband voice supports G.722.

Steve