System.CalloutException: IO Exception: Detect premature EOF while hitting external server

In SFDC to SAP PI integration​n, when hitting to SAP PI server got System.CalloutException: IO Exception: Detect premature EOF .


Solution:

The receiving server had a firewall blocking the SF IP addresses therefore we have to whitelist our IP address with external server.

 Hope this info is useful to others in services !!

Thanks
Gaurav