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

[mgraves at mstvp.com]

We should also be very clear that the Siren codecs are supported on the
Polycom SoundStation conference phones and the VVX-1500 Business Media
Phones. These codecs are not supported in the SoundPoint desk phones.
The SoundPoint series support the more basic G.722 codec in the
IP335/450/550/560/650/670 models.

Michael Graves
mgraves  mstvp.com
o(713) 861-4005
c(713) 201-1262
sip:mjgraves at mstvp.onsip.com
skype mjgraves

> -------- Original Message --------
> Subject: Re: [asterisk-users] Are the Siren7 and Siren14 the G.722 HD
> voice codecs?
> From: Steve Underwood <steveu at coppice.org>
> Date: Wed, January 05, 2011 6:09 pm
> To: Asterisk Users Mailing List - Non-Commercial Discussion
> <asterisk-users at lists.digium.com>
> 
> 
> On 01/06/2011 12:05 AM, Kevin P. Fleming wrote:
> > 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.
> >
> I am unclear how compatible or incompatible the bitstreams may be. What 
> I know (from implementing these codecs) is that the source code Polycom 
> provide licencees, as the basis for developing their own G.722.1 and 
> G.722.1C codecs, has several comments referring to things not being 
> quite the same as Siren7/Siren14. However, they don't hand out the 
> actual Siren7/Siren14 source code, so I don't know how much divergence 
> there is.
> 
> Steve
> 
> 
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