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

[Kevin P. Fleming]

On 01/05/2011 07:07 AM, Steve Underwood wrote:
> 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.

Asterisk actually supports both the Siren* and G.722.1* names in SDP 
negotiations. I wasn't aware there were bitstream incompatibilities 
between the Siren* and G.722.1* variants, even though the code may be 
slightly different... so Asterisk uses a single codec module for both 
variants.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
skype: kpfleming | jabber: kfleming at digium.com
Check us out at www.digium.com & www.asterisk.org