TCP/IP is using some of the Application layer protocols in addition to Transport and Internet layer protocols. Those protocols are used for transforming user requests to network friendly format through the TCP or UDP with IP.
Telnet
It is protocol used for remote login through the TCP/IP. It is using port 23 for the connection and behavior on the remote machine is ...
What is DDNS (Dynamic DNS) and what it is used for? DNS is used for host location and can be used effectively for that purpose, when the IP is of the host is relatively constant (static). However, nowadays, due to impossibility to assign static IP for every device in the network, most users are using dynamic IP subscription from their network ...