The following code will work for a remote client request to SQL 2008 and newer.
Note: The local machine address (local_net_address) is that of the SQL Server while client_net_address is the address of the remote computer you have used to make the request.
SELECT @@SERVERNAME AS ServerName ,CONNECTIONPROPERTY('net_transport') AS net_transport ,CONNECTIONPROPERTY('protocol_type') AS protocol_type ,CONNECTIONPROPERTY('auth_scheme') AS auth_scheme ,CONNECTIONPROPERTY('local_net_address') AS local_net_address ,CONNECTIONPROPERTY('local_tcp_port') AS local_tcp_port ,CONNECTIONPROPERTY('client_net_address') AS client_net_address