Trying to configure Asterisk 11 Cert with G722.1C. I have installed the latest binary for Siren14:

srv-echo*CLI> siren14 show version Digium Siren14 Module Version 11.0_1.0.5 (optimized for opteron_sse3_64)

According to this list post in 2012 Asterisk supports G.722.1 Annex C (also known as Siren14), and this can be configured in a config file as either
‘g7221c’ or ‘siren14’:

http://lists.digium.com/pipermail/asterisk-users/2012-February/270218.html

However when setting allow=g7221c Asterisk will throw the following error:

[Mar 27 00:32:39] WARNING[1950]: frame.c:821 ast_parse_allow_disallow:
Cannot allow unknown format ‘g7221c’
[Mar 27 00:32:39] WARNING[1950]: chan_sip.c:31786 reload_config: Codec configuration errors found in line 9 : allow = g7221c

The setting for allow=siren14 does work. The issue is the Polycom VVX600
phones do not support Siren14, rather the G722.1C implementation. The module was loaded properly as well:

[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1004 load_module: ITU
G.722.1 Annex C (Siren14, licensed from Polycom) transcoding module version
11.0_1.0.5 (This seems like a good start)
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1005 load_module:
Copyright (C) 1999-2009 Digium, Inc.
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1006 load_module: This module is supplied under a commercial license granted by Digium, Inc.
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1007 load_module: Please see the full license text supplied in the accompanying
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1008 load_module:
“LICENSE” file, or ask for a copy from Digium.
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1009 load_module: This product includes software from the Speex library. Please see
[Mar 26 12:59:11] NOTICE[51170]: codec_siren14.c:1010 load_module: the accompanying “SPEEX_LICENSE” file for license information.
[Mar 26 12:59:11] == Registered translator ‘siren14tolin16’ from format siren14 to slin16, table cost, 960000, computational cost 14044
[Mar 26 12:59:11] == Registered translator ‘lin16tosiren14’ from format slin16 to siren14, table cost, 825000, computational cost 19581
[Mar 26 12:59:11] == Registered translator ‘siren14tolin8’ from format siren14 to slin, table cost, 960000, computational cost 18572
[Mar 26 12:59:11] == Registered translator ‘lin8tosiren14’ from format slin to siren14, table cost, 825000, computational cost 17958
[Mar 26 12:59:11] Loaded codec_siren14.so => (ITU G.722.1 Annex C
(Siren14, licensed from Polycom) Encoder/Decoder (optimized for opteron_sse3_64))

When trying to setup a call with just allow=siren14 the VVX600 would offer this:

[Mar 26 13:12:03] — (16 headers 14 lines) –