No Incoming call in Xlite

Hai Guys,

Currently i have LAN network with 3 PC connected with switch. 1 For asterisk server and 2 for Xlite each other.

When i am trying to dial another user of SIP with X-Lite, there is no incoming pop up call the target in dialing user X-Lite. What is the problem ? any one have same case ?

Best Regards,