FAILURE CASE - 1.8.1.1 to 1.8.1.1

This is the log from the originating 1.8.1.1 system:

-- Executing [958@onstate-jrc2:2] Dial("SIP/jrc-000034f6", "IAX2/iax.covert.org/958,10") in new stack
-- Called iax.covert.org/958
Tx-Frame Retry[000] -- OSeqno: 000 ISeqno: 000 Type: IAX     Subclass: NEW    
   Timestamp: 00018ms  SCall: 05239  DCall: 00000 [72.93.205.52:4569]
   VERSION         : 2
   CALLED NUMBER   : 958
   CODEC_PREFS     : ()
   CALLING NUMBER  : 28
   CALLING PRESNTN : 0
   CALLING TYPEOFN : 0
   CALLING TRANSIT : 0
   CALLING NAME    : Snom 28
   LANGUAGE        : en
   FORMAT          : 4
   FORMAT2         : ulaw
   CAPABILITY      : 65407
   CAPABILITY2     : unknown
   ADSICPE         : 2
   DATE TIME       : 2011-01-06  09:14:30

Rx-Frame Retry[Yes] -- OSeqno: 000 ISeqno: 001 Type: IAX     Subclass: CTOKEN 
   Timestamp: 00018ms  SCall: 00001  DCall: 05239 [72.93.205.52:4569]
   CALLTOKEN       : 51 bytes

Tx-Frame Retry[000] -- OSeqno: 000 ISeqno: 000 Type: IAX     Subclass: NEW    
   Timestamp: 00037ms  SCall: 05239  DCall: 00000 [72.93.205.52:4569]
   VERSION         : 2
   CALLED NUMBER   : 958
   CODEC_PREFS     : ()
   CALLING NUMBER  : 28
   CALLING PRESNTN : 0
   CALLING TYPEOFN : 0
   CALLING TRANSIT : 0
   CALLING NAME    : Snom 28
   LANGUAGE        : en
   FORMAT          : 4
   FORMAT2         : ulaw
   CAPABILITY      : 65407
   CAPABILITY2     : unknown
   ADSICPE         : 2
   DATE TIME       : 2011-01-06  09:14:30
   CALLTOKEN       : 51 bytes

Rx-Frame Retry[ No] -- OSeqno: 000 ISeqno: 001 Type: IAX     Subclass: REJECT 
   Timestamp: 00001ms  SCall: 00690  DCall: 05239 [72.93.205.52:4569]
   CAUSE           : Unable to negotiate codec
   CAUSE CODE      : 58

[06-Jan-2011 09:14:31.62] WARNING[32292]: chan_iax2.c:10652 socket_process: Call rejected by 72.93.205.52:
 Unable to negotiate codec
Tx-Frame Retry[-01] -- OSeqno: 001 ISeqno: 001 Type: IAX     Subclass: ACK    
   Timestamp: 00001ms  SCall: 05239  DCall: 00690 [72.93.205.52:4569]
-- Hungup 'IAX2/72.93.205.52:4569-5239'
  == Everyone is busy/congested at this time (1:0/0/1)

Here is the view from the terminating 1.8.1.1 system for an unsuccessful call from the 1.8.1.1 system

Rx-Frame Retry[ No] -- OSeqno: 000 ISeqno: 000 Type: IAX     Subclass: NEW    
   Timestamp: 00006ms  SCall: 03607  DCall: 00000 [63.210.44.150:4569]
   VERSION         : 2
   CALLED NUMBER   : 958
   CODEC_PREFS     : ()
   CALLING NUMBER  : 28
   CALLING PRESNTN : 0
   CALLING TYPEOFN : 0
   CALLING TRANSIT : 0
   CALLING NAME    : Snom 28
   LANGUAGE        : en
   FORMAT          : 4
   FORMAT2         : unknown
   CAPABILITY      : 65407
   CAPABILITY2     : unknown
   ADSICPE         : 2
   DATE TIME       : 2011-01-06  09:21:00

Rx-Frame Retry[ No] -- OSeqno: 000 ISeqno: 000 Type: IAX     Subclass: NEW    
   Timestamp: 00030ms  SCall: 03607  DCall: 00000 [63.210.44.150:4569]
   VERSION         : 2
   CALLED NUMBER   : 958
   CODEC_PREFS     : ()
   CALLING NUMBER  : 28
   CALLING PRESNTN : 0
   CALLING TYPEOFN : 0
   CALLING TRANSIT : 0
   CALLING NAME    : Snom 28
   LANGUAGE        : en
   FORMAT          : 4
   FORMAT2         : unknown
   CAPABILITY      : 65407
   CAPABILITY2     : unknown
   ADSICPE         : 2
   DATE TIME       : 2011-01-06  09:21:00
   CALLTOKEN       : 51 bytes

[Jan  6 09:21:01] NOTICE[23781]: chan_iax2.c:10512 socket_process: Rejected connect attempt from 63.210.44.150,
 requested/capability '0x400000000000000 (nothing)'/'0x7fff000000000000 (nothing)' incompatible with
 our capability '0xff7f (g723|gsm|ulaw|alaw|g726|adpcm|slin|g729|speex|ilbc|g726aal2|g722|slin16|siren7|siren14)'.
Tx-Frame Retry[000] -- OSeqno: 000 ISeqno: 001 Type: IAX     Subclass: REJECT 
   Timestamp: 00015ms  SCall: 01680  DCall: 03607 [63.210.44.150:4569]
   CAUSE           : Unable to negotiate codec
   CAUSE CODE      : 58

Rx-Frame Retry[ No] -- OSeqno: 001 ISeqno: 001 Type: IAX     Subclass: ACK    
   Timestamp: 00015ms  SCall: 03607  DCall: 01680 [63.210.44.150:4569]