I have just installed Freeswitch and have spent the day searching the wiki for an answer. My soft phone on Linux and the Grand Stream hard phone are finally talking to the switch. However the Grand Stream (on extension 101) requires the soft phone to call it as 101@192.168.2.99 whereas the Grand Stream can call the softphone at extension 1000 without an extension. The soft phone is not on the same computer as the switch. The configuration files are identical except for the extensions and passwords. I was getting a message like: 2010-03-28 13:46:52.514487 [WARNING] sofia_reg.c:1872 Can't find user [101@192.168.2.51] You must define a domain called '192.168.2.51' in your directory and add a user with the id="101" attribute and you must configure your device to use the proper domain in it's authentication credentials. But I have no idea how to either correct this problem or set a domain anywhere. There is no mention of domain in the configuration for the Grand Stream and changing the user to 101@192.168.2.51 in the phone and in the config didn't work. Here are the respective config files: <include> <user id="1000"> <params> <param name="password" value="1234"/> <param name="vm-password" value="1234"/> </params> <variables> <variable name="toll_allow" value="domestic,international,local"/> <variable name="accountcode" value="1000"/> <variable name="user_context" value="default"/> <variable name="effective_caller_id_name" value="Extension 1000"/> <variable name="effective_caller_id_number" value="1000"/> <variable name="outbound_caller_id_name" value="$${outbound_caller_name}"/> <variable name="outbound_caller_id_number" value="$${outbound_caller_id}"/> <variable name="callgroup" value="techsupport"/> </variables> </user> </include> <include> <user id="101" mailbox="101"> <params> <param name="password" value="secret"/> <param name="vm-password" value="1234"/> </params> <variables> <variable name="toll_allow" value="domestic,international,local"/> <variable name="accountcode" value="101"/> <variable name="user_context" value="default"/> <variable name="effective_caller_id_name" value="Extension 101"/> <variable name="effective_caller_id_number" value="101"/> <variable name="outbound_caller_id_name" value="$${outbound_caller_name}"/> <variable name="outbound_caller_id_number" value="$${outbound_caller_id}"/> <variable name="callgroup" value="techsupport"/> </variables> </user> </include> Thanks for any assistance. Jim.