We had already tried deleting the ext and lettig it auto create with the same results.
Here are the monitor logs when we tried to call from a digital station to the aastra.
8889996mS SIP Call Tx: phone
INVITE sip:4999@192.168.42.4;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bK9921b2229798a2948b8b025bddc97193
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Contact: "Extn201" <sip:201@192.168.42.1:5060;transport=udp>
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Content-Type: application/sdp
Supported: timer
P-Asserted-Identity: "Extn201" <sip:201@192.168.42.1:5060>
Content-Length: 298
v=0
o=UserA 480495283 3995838770 IN IP4 192.168.42.1
s=Session SDP
c=IN IP4 192.168.42.1
t=0 0
m=audio 49152 RTP/AVP 0 8 18 4 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:4 G723/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
8889996mS SIP Tx: UDP 192.168.42.1:5060 -> 192.168.42.4:5060
INVITE sip:4999@192.168.42.4;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bK9921b2229798a2948b8b025bddc97193
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Contact: "Extn201" <sip:201@192.168.42.1:5060;transport=udp>
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Content-Type: application/sdp
Supported: timer
P-Asserted-Identity: "Extn201" <sip:201@192.168.42.1:5060>
Content-Length: 298
v=0
o=UserA 480495283 3995838770 IN IP4 192.168.42.1
s=Session SDP
c=IN IP4 192.168.42.1
t=0 0
m=audio 49152 RTP/AVP 0 8 18 4 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:4 G723/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
8890064mS SIP Rx: UDP 192.168.42.4:5060 -> 192.168.42.1:5060
SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9921b2229798a2948b8b025bddc97193;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, OPTIONS, UPDATE, PRACK, SUBSCRIBE, INFO
Allow-Events: talk, hold, conference, LocalModeStatus
Contact: "4999" <sip:4999@192.168.42.4:5060;transport=udp>;+sip.instance="<urn:uuid:00000000-0000-1000-8000-00085D31A674>"
Server: Aastra 6731i/2.6.0.2010
Supported: gruu, path
Content-Length: 0
8890066mS SIP Call Rx: phone
SIP/2.0 180 Ringing
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9921b2229798a2948b8b025bddc97193;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, OPTIONS, UPDATE, PRACK, SUBSCRIBE, INFO
Allow-Events: talk, hold, conference, LocalModeStatus
Contact: "4999" <sip:4999@192.168.42.4:5060;transport=udp>;+sip.instance="<urn:uuid:00000000-0000-1000-8000-00085D31A674>"
Server: Aastra 6731i/2.6.0.2010
Supported: gruu, path
Content-Length: 0
8895149mS RES: Mon 23/4/2012 16:22:18 FreeMem=61248976(1) CMMsg=3 (6) Buff=5200 959 998 7423 5 Links=6737
8895149mS RES2: IP 500 V2 8.0(18) Tasks=46 RTEngine=0 CMRTEngine=0 ExRTEngine=0 Timer=61 Poll=0 Ready=0 CMReady=0 CMQueue=0 VPNNQueue=0 Monitor=1 SSA=2 ASC=1 SYS=MNTD OPT=UMNT SDSPD=2034
8897779mS SIP Rx: UDP 192.168.42.4:5060 -> 192.168.42.1:5060
SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9921b2229798a2948b8b025bddc97193;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, OPTIONS, UPDATE, PRACK, SUBSCRIBE, INFO
Allow-Events: talk, hold, conference, LocalModeStatus
Contact: "4999" <sip:4999@192.168.42.4:5060;transport=udp>;+sip.instance="<urn:uuid:00000000-0000-1000-8000-00085D31A674>"
Server: Aastra 6731i/2.6.0.2010
Supported: gruu, path, timer, replaces
Content-Type: application/sdp
Content-Length: 325
v=0
o=MxSIP 0 0 IN IP4 192.168.42.4
s=SIP Call
c=IN IP4 192.168.42.4
t=0 0
m=audio 3000 RTP/AVP 0 8 18 4 4 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=rtpmap:4 G723/8000
a=rtpmap:4 G723/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:18 annexb=no
a=fmtp:101 0-15
a=ptime:20
a=sendrecv
8897783mS SIP Call Rx: phone
SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9921b2229798a2948b8b025bddc97193;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 INVITE
Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, OPTIONS, UPDATE, PRACK, SUBSCRIBE, INFO
Allow-Events: talk, hold, conference, LocalModeStatus
Contact: "4999" <sip:4999@192.168.42.4:5060;transport=udp>;+sip.instance="<urn:uuid:00000000-0000-1000-8000-00085D31A674>"
Server: Aastra 6731i/2.6.0.2010
Supported: gruu, path, timer, replaces
Content-Type: application/sdp
Content-Length: 325
v=0
o=MxSIP 0 0 IN IP4 192.168.42.4
s=SIP Call
c=IN IP4 192.168.42.4
t=0 0
m=audio 3000 RTP/AVP 0 8 18 4 4 101
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:18 G729/8000
a=rtpmap:4 G723/8000
a=rtpmap:4 G723/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:18 annexb=no
a=fmtp:101 0-15
a=ptime:20
a=sendrecv
8897785mS SIP Call Tx: phone
ACK sip:4999@192.168.42.4:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bKb971b69b33533eb6508fe9ea4d4b5c6e
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 ACK
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Content-Length: 0
8897785mS SIP Tx: UDP 192.168.42.1:5060 -> 192.168.42.4:5060
ACK sip:4999@192.168.42.4:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bKb971b69b33533eb6508fe9ea4d4b5c6e
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699267 ACK
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Content-Length: 0
8897792mS SIP Call Tx: phone
BYE sip:4999@192.168.42.4:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bK9a68c1deb2bc0eb9e72df17c646ab92f
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699268 BYE
Contact: "Extn201" <sip:201@192.168.42.1:5060;transport=udp>
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Supported: timer
Content-Length: 0
8897793mS SIP Tx: UDP 192.168.42.1:5060 -> 192.168.42.4:5060
BYE sip:4999@192.168.42.4:5060;transport=udp SIP/2.0
Via: SIP/2.0/UDP 192.168.42.1:5060;rport;branch=z9hG4bK9a68c1deb2bc0eb9e72df17c646ab92f
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699268 BYE
Contact: "Extn201" <sip:201@192.168.42.1:5060;transport=udp>
Max-Forwards: 70
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, INFO, SUBSCRIBE, REGISTER, PUBLISH, UPDATE
Supported: timer
Content-Length: 0
8897796mS PRN: Config Write Wake Up
8897942mS SIP Rx: UDP 192.168.42.4:5060 -> 192.168.42.1:5060
SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9a68c1deb2bc0eb9e72df17c646ab92f;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699268 BYE
Server: Aastra 6731i/2.6.0.2010
Content-Length: 0
8897943mS SIP Call Rx: phone
SIP/2.0 200 OK
Via: SIP/2.0/UDP 192.168.42.1:5060;rport=5060;branch=z9hG4bK9a68c1deb2bc0eb9e72df17c646ab92f;received=192.168.42.1
From: "Extn201" <sip:201@192.168.42.1>;tag=51eb124a68965bd8
To: "Extn4999" <sip:4999@192.168.42.1;transport=udp>;tag=2981392499
Call-ID: e721053f89567400a886308fddaaf6a3@192.168.42.1
CSeq: 587699268 BYE
Server: Aastra 6731i/2.6.0.2010
Content-Length: 0