Freepbx internal sip to sip extension always diverting to voicemail

I have a basic freepbx installation (asterisk now) on which I have created 3 sip extensions.
Dialing from extension 2002 to 2001 works fine, the extension rings and can be answered.
however
dialing from extension 2001 to 2002 does not work and instead I hear “the person at extension 2002 is not available…” and I am directed to voice mail.

Extension 2001 is logged in from a cisco ip phone
Extension 2002 is an ekiga sip soft phone on linux

I’ve been through the verbose logging output and enabled sip logging but am unable to understand why extension 2002 cannot accept incoming calls. I’ve included the sip_additional.conf, extensions_additional.conf and the sip debug log file.

I’ve been through these files trying to spot why the configuration is causing this to occur but have been unsuccessful. I would really appreciate a 2nd opinion in case I’m missing something obvious.

Thanks in advance.

sip_additional.conf

;--------------------------------------------------------------------------------;
; Do NOT edit this file as it is auto-generated by FreePBX. All modifications to ;
; this file must be done via the web gui. There are alternative files to make ;
; custom modifications, details at: http://freepbx.org/configuration_files ;
;--------------------------------------------------------------------------------;
;

[2000]
deny=0.0.0.0/0.0.0.0
secret=2000ab
dtmfmode=rfc2833
canreinvite=no
context=from-internal
host=dynamic
trustrpid=yes
sendrpid=no
type=friend
nat=no
port=5060
qualify=yes
qualifyfreq=60
callgroup=
pickupgroup=
dial=SIP/2000
[email protected]
permit=0.0.0.0/0.0.0.0
callerid=SIPMobile <2000>
callcounter=yes
faxdetect=no

[2001]
deny=0.0.0.0/0.0.0.0
secret=2001ab
dtmfmode=rfc2833
canreinvite=no
context=from-internal
host=dynamic
trustrpid=yes
sendrpid=no
type=friend
nat=no
port=5060
qualify=yes
qualifyfreq=60
callgroup=
pickupgroup=
dial=SIP/2001
[email protected]
permit=0.0.0.0/0.0.0.0
callerid=Office <2001>
callcounter=yes
faxdetect=no

[2002]
deny=0.0.0.0/0.0.0.0
secret=2002ab
dtmfmode=rfc2833
canreinvite=no
context=from-internal
host=dynamic
trustrpid=yes
sendrpid=no
type=friend
nat=no
port=5060
qualify=yes
qualifyfreq=60
callgroup=
pickupgroup=
dial=SIP/2002
[email protected]
permit=192.168.0.24/255.255.255.0
callerid=OfficePCSoftPhone <2002>
callcounter=yes
faxdetect=no

extensions_additional.conf
Download extensions_additional.conf from SendSpace

sip debug log file
Download full.12 from SendSpace