This is one of the first questions of a Network Engineer: What is a Network Protocol? A Network Protocol is a set of rules, standards, precedures that provide the communication of devices in a network. With all these features, Network Protocols shows how to beahve data between these devices. These standards define anything about this communicationlike physical topologies, cabling, access method etc.
Network Protocol is a very general definition. Above, we have also answered the question What is a Network Protocol? But what are the types of these protocols? There are many different areas, communication types, concepts etc. These types are also define in Wikipedia.
There are different network protocols that work in different layers of OSI Model and TCPIP Model. If we devide these protocols into categories, we can determine the below protocol categories.
There are different network protocols that work in different layers of OSI Model and TCPIP Model. If we devide these protocols into categories, we can determine the below protocol categories.
- Switching Protocols (Layer 2 Protocols)
- Routing Protocols (Layer 3 Protocols)
- Transport Layer Protocols
- Application Layer Protocols
Layer 2 Network Protocols
Swithcing is the Layer 2 (Datalink Layer) of OSI Model. It is also Data Link Layer for TCPIP Model.There are various network protocols in this layer. Spanning Tree Protocols like STP, RSTP, PVST+ are some of these protocols. PPP, HDLC, ATM, Frame-Relay are also Layer 2 network protocols that are also called WAN Protocols.Layer 3 Network Protocols
In Layer 3 of OSI Model or TCPIP Model, two types of protocols exists. These are Routed Protocols and Routing Protocols. What are these Routed Protocols? These Routed Protocols are wellknown IP and old IPX protocols. IPv4 and IPv6 are the sub types of these Routed Protocol IP. And there are also Routing Protocols that are RIP, EIGRP, OSPF, IS-IS and BGP. These protocols are Routing Protocols but we can also divide these protocols into different types according to their working styles. These types can be:- Interior Gateway Protocols
- Exterior Gateway Protocols
- Distance Vector Protocols
- Link-State Protocols
- Hybrid Protocols
- Path Vector Protocols
Transport Layer Protocols
Transport Layer Protocols are wellknow protocols like TCP, UDP and SCTP. These protocols are responsible from the sessions of a communication generally. They has different characteristics and they are used for different purposes. But one of the most important similar characteristic of these protocols are, they are all the answers of What is a Network Protocol? question. Here, we do not explain all the details of these network protocols. If you would like to learn all these details, you can check the related protocol lessons.Application Layer Protocols
Application layer is the layer that has too much network protocols. These are various protocols that work in this layer. For example we can devide these layer like below:- Web Protocols
- Network Management
- File Transfer Protocols