The Protocols exist at several levels in a telecommunication connection. For example, there are protocols for the data interchange at the hardware device level and protocols for data interchange at the application program level. In the Open Systems Interconnection (OSI) model, there are one or more protocols at each layer in the telecommunication exchange. The protocols can recognize and observer in both ends of the exchange. Protocols are often described in an industry or international standard.
A common example, TCP/IP Internet protocols consists of
- Transmission Control Protocol (TCP) uses a set of rules for exchanging messages at the information packet level with other Internet points
- Internet Protocol (IP) uses a set of rules to send and receive messages at the Internet address level
- Additional protocols including Hypertext Transfer Protocol (HTTP) and File Transfer Protocol (FTP) has defined sets of rules to use with corresponding programs elsewhere on the Internet
There are many other Internet protocols, such as the Border Gateway Protocol (BGP) and the Dynamic Host Configuration Protocol (DHCP).