[Serusers] How to use SER with SIP Communicator

Hi friends, I want to work with SIP on a LAN. For this today I have downloaded and installed SER on my local machine. I have managed to login. However I am not able to dial up another user who has logged-in. Both of us are on the same LAN. The error is "Remote part returned error response - 408- Request Timeout" I have kept the domain name as IP of my machine 10.0.0.101, where SER has been installed. The output of "select * from subscriber;" is as follows +----------------------------------+----------+------------+----------+------------+-----------+-------+-------------------+---------------------+---------------------+------------------------------------------+------+------------------+----------+----------------------------------+----------------------------------+-------+------------+----------+---------+ | phplib_id | username | domain | password | first_name | last_name | phone | email_address | datetime_created | datetime_modified | confirmation | flag | sendnotification | greeting | ha1 | ha1b | perms | allow_find | timezone | rpid | +----------------------------------+----------+------------+----------+------------+-----------+-------+-------------------+---------------------+---------------------+------------------------------------------+------+------------------+----------+----------------------------------+----------------------------------+-------+------------+----------+---------+ | ed679a94c2d06c2853e8eac7ccc12359 | john | 10.0.0.101 | john | | | | johnv(a)aftek.com | 2005-03-15 12:25:23 | 2005-03-15 12:26:35 | | o | | | ed679a94c2d06c2853e8eac7ccc12359 | b4bf9c3408f165f59af7eb72438a8e95 | NULL | 0 | NULL | john | | b8ca68a4e7eafeb5e4c7ec9dc3a9eaf2 | sandeep | 10.0.0.101 | sandeep | | | | sandeep(a)aftek.com | 2005-03-15 12:26:59 | 2005-03-15 12:27:18 | | o | | | b8ca68a4e7eafeb5e4c7ec9dc3a9eaf2 | e6705f3068a0bf4c45a0ec2689d55b21 | NULL | 0 | NULL | sandeep | I am pasting some lines from console of sip-communicator.sh Call-ID: 224990ce9dffd68b151bc394f811f687(a)10.0.0.101 CSeq: 1 INVITE From: "John Varghese" <sip:john@10.0.0.101:27882;transport=udp>;tag=22845412 To: <sip:sandeep@10.0.0.101>;tag=a6a1c5f60faecf035a1ae5b6e96e979a-c802 Via: SIP/2.0/UDP 10.0.0.101:27882;branch=z9hG4bK0de890eafa356f841c05dc95564ea035 Server: Sip EXpress router (0.8.14 (i386/linux)) Warning: 392 10.0.0.101:5060 "Noisy feedback tells: pid=3784 req_src_ip=10.0.0.101 req_src_port=27882 in_uri=sip:sandeep@10.0.0.101 out_uri=*sip:61.11.16.124:5060*;transport=udp via_cnt==0" Content-Length: 0 Can anybody please help John