help with server in mw2

i have created one server in mw2 alterinwet but and all the ports it is ok but when i open the server i see this <<Dropping all reliable packets for client at 'loopback' since they haven't ack'd a reliable message in 20000ms
Dropping all reliable packets for client at 'loopback' since they haven't ack'd a reliable message in 20000ms
Sending heartbeat to server.alteriw.net
Dropping all reliable packets for client at 'loopback' since they haven't ack'd a reliable message in 20000ms>> and my friend try to connect he couldnt. he said to me that<<unabled to connect to host>> why?

F-f-f-f-f--f-firewall...