ftp waits for longer time to reply

If i fire followin command on unix (linux/solaris) and windows
ftp serverX where serverX is not in the network,
it takes more time to get reply [connection timed out] on unix(3-4 mins) rather windows(1 min),

can anybody tell me why this happens? and how to reduce this time span?

Probably DNS delay. Either properly configure DNS or just remove completely