EPIC Networks

Function of the Application Layer (Layer-7) The application layer is responsible for integrating network services with the operating system. The application layer really provides the interface between the applications and the rest of the network. Different protocols are associated with the application layer, such as HTTPS, HTTP, TELNET, FTP, SMTP and many others. We talk about these protocols as being in the application layer, but in reality, most of these protocols actually extend down through the session layer. 

Port Check and data transfer verification The netcat utility or nc basically given in any linux and its working TCP/IP networks.nc tool is well known to System Administrators and Network Administrators as it has a wide range of capabilities. The Netcat utility is used for  Netcat can open TCP connections,  send UDP packets of data, listen on arbitrary TCP and UDP ports, carry out port scanning, transfer data from one server to another.  Server :- nc - l -p {port number}  [data]  Client :- nc {server Ip} {Portnumber opened}  [data]