Thank you guys. it is fixed!!!

We are importing data as "Select * into....." through sql script which we run in SSIS. For remote server properties, connection timeout and query time out was set to 0 by default. I did google found out that connection timeout 0 means 20 secs (i dont know it is true or not) but I followed it and changed it to 3600 and query time to 7200. it solved the issue.

I came to know one more thing that Remote Query Timeout setting a server level actually is for outgoing connection and it has NO impact on incoming connection. I was mistakenly tyring to configure the "SourceServer". Then after the research, I changed the settings under remote connection properties of the "DestinationServer".

Thanks

Shriji