Call establishment

Hi all
I have generated call on sip with xlite to smart handset (PDA) on a asterisk server.
Now can i generate a call through my smart handset that is connect with DHCP server on one side & on the other side its a asterisk server on the XLite (SIP MODE)

                                   call establishment

smart ------> dhcp <----------------------- > asterisk-------> Xlite
handset server server

Does anyone has the solution

Thanks in advance