Summary:ASTERISK-12340: G722 negociation problem with Aastra 5xi phones
Reporter:olivier1010 (olivier1010)Labels:
Date Opened:2008-07-08 09:08:06Date Closed:2011-06-07 14:03:21
Versions:Frequency of
Environment:Attachments:( 0) sip_debug.txt
Using Aastra firmware 2.2.1 on serie 5xi, the G722 mode does not work correctly.

Asterisk negociate only at G722/8 Khz, giving a sound quality not better and less natural than G711.

strangely, when calling voicemail, (using G722/16 songs), G722 is really in 16 khz mode.

G722 is first priority in the aastra setup. Here we can't choose wich mode /8 or /16 is first priority. G722/8 is certainly the first choice in the phone.

I think that to allow for G722/16, asterisk should force using it instead of relying on the phone codec priority.

Last, any possibility to have G711u/16 G711a/16 codecs for asterisk 1.6 ? (supported by aastra).

G722 is not as good as G711. The song is sligtly compressed and unnatural, not as compressed as G729.1, but we can hear the difference.

G711/16 is 128 kbits/sec but it is not a problem for LAN calls.

Thanks for your listening.

Comments:By: Mark Michelson (mmichelson) 2008-07-08 18:52:48

Hmm, correct me if I'm wrong, but there is no such thing as 8 khz g.722. I know that SDP's which specify g.722 show G722/8000 due to an error made in RFC 1890. The codec still operates at 16 khz though.

By: Mark Michelson (mmichelson) 2008-07-08 18:58:59

I guess before I jump to conclusions, could you attach a SIP debug from an attempt to use g.722?

By: olivier1010 (olivier1010) 2008-07-09 12:24:10

The G722/8000 notation was confunsing me.

Nevertheless i need to make more tests to verify the real bandwith off the phone in G722 mode. Could be an Aastra issue as this capability is really new.

Somethink is sure : the phone is able to reproduce a 8 Khz bandwith (16 Khz sampling), as we can hear very clearly the difference with the G722 voicemail prompts.

With voice, from phone to phone, it is clear that we do not have 8 Khz bandwith in G722 mode.

I need to make more tests to see if it is a phone firmaware problem or an asterisk problem, staying at 8 Khz when exchanging RTP data between two phones.

Issuing "Show channels" show G722 mode on the two legs of the call. So if there is an asterisk resampling problem it is internally, this is not a negociation problem as all seems ok in the sip debug and show channels.

Next step is to make tests with reinvite=yes in G722 mode to bypass asterisk and see if there is a difference.

For your information, here is a list of the supported codec for aastra phones, where we can see the interesting G711a / G711u /16, as well as linear /8 and /16 who should be possible to interface with asterisk linear codec.

I suppose that linear is a 16 bit codec. if it is 8 bits it does not have any usefullness.

m=audio 3000 RTP/AVP 0 18 106 107 113 110 111 112 98 97 115 96 9 8 101
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=rtpmap:106 BV16/8000
a=rtpmap:107 BV32/16000
a=rtpmap:113 L16/16000
a=rtpmap:110 PCMU/16000
a=rtpmap:111 PCMA/16000
a=rtpmap:112 L16/8000
a=rtpmap:98 G726-16/8000
a=rtpmap:97 G726-24/8000
a=rtpmap:115 G726-32/8000
a=rtpmap:96 G726-40/8000
a=rtpmap:9 G722/8000
a=rtpmap:8 PCMA/8000

I will come back with more informations after some new tests.

Best regards.

By: Jason Parker (jparker) 2008-11-18 16:32:50.000-0600

No response from reporter in several months.  Additionally, there have been quite a few G722 fixes made.

Please reopen if this is still an issue with the latest version of Asterisk.