I'm having the same problem as the above poster. Here is a verbose output of my logfile:
Please note, I'm configured to SIP trunks which provide our dialtone. They require e164 number format for dialing. I'm running this under linux, ClearOS 5.2 (CentOS base).
SIP/2.0 200 Ok
Via: SIP/2.0/UDP 192.168.2.63:2048;branch=z9hG4bK-fldyvxgnso0j;rport=2048
From: <sip:40@192.168.2.160>;tag=uhu2hvbrm4
To: <sip:40@192.168.2.160>;tag=a194625d70
Call-ID: 3c2670679951-nwr4iraahml8
CSeq: 549 REGISTER
Contact: <sip:40@192.168.2.63:2048>;expires=361
Supported: path
Date: Wed, 8 Dec 2010 19:29:54 GMT
Content-Length: 0
[9] 2010/12/08 19:31:36: UDP: Opening socket on 0.0.0.0:53642
[9] 2010/12/08 19:31:36: UDP: Opening socket on 0.0.0.0:53643
[9] 2010/12/08 19:31:36: UDP: Opening socket on [::]:53642
[9] 2010/12/08 19:31:36: UDP: Opening socket on [::]:53643
[8] 2010/12/08 19:31:36: Could not find a trunk (3 trunks)
[9] 2010/12/08 19:31:36: Resolve 773: aaaa udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 773: a udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 773: udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 774: aaaa udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 774: a udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 774: udp 192.168.2.63 2048
[8] 2010/12/08 19:31:36: Tagging request with existing tag
[7] 2010/12/08 19:31:36: Set packet length to 20
[6] 2010/12/08 19:31:36: Sending RTP for 3c273d2e5acf-uu4dkwylvt81 to 192.168.2.63:51454, codec not set yet
[9] 2010/12/08 19:31:36: Resolve 775: aaaa udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 775: a udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 775: udp 192.168.2.63 2048
[8] 2010/12/08 19:31:36: Call from an user 40
[8] 2010/12/08 19:31:36: To is <sip:+91831xxxxxxx@192.168.2.160;user=phone>, user 0, domain 1 <!--Edited out the number-->
[8] 2010/12/08 19:31:36: From user 40
[8] 2010/12/08 19:31:36: Set the To domain based on From user 40@pbx.company.com
[8] 2010/12/08 19:31:36: Call state for call object 29: idle
[9] 2010/12/08 19:31:36: Dialplan: Evaluating !^9([0-9]*)@.*!sip:\+\1@\r;user=phone!i against +91831xxxxxxx@192.168.2.160 <!--Also edited out the number-->
[7] 2010/12/08 19:31:36: set_codecs: for 3c273d2e5acf-uu4dkwylvt81 codecs "", codec_preference count 6
[7] 2010/12/08 19:31:36: Set packet length to 20
[9] 2010/12/08 19:31:36: Resolve 776: aaaa udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 776: a udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 776: udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 777: aaaa udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 777: a udp 192.168.2.63 2048
[9] 2010/12/08 19:31:36: Resolve 777: udp 192.168.2.63 2048