The TCP/IP Protocol Suite

Internet Protocol (IP)

A Network-layer (OSI Layer 3) protocol that is responsible for routing individual datagrams and addressing. This protocol is a connectionless protocol and acts as an intermediary between high protocol layers and the network. It can carry either TCP or UDP as its payload. When used with TCP, this protocol provides the connection and TCP provides reliability.

TCP

A connection-oriented, guaranteed-delivery protocol used to send data packets between devices over a network such as the Internet. It sends data, waits for an acknowledgement, and retransmits if necessary.

UDP

A connectionless Transport-layer protocol in the IP suite. This protocol is a best-effort delivery protocol. Because it does not wait for acknowledgement, it provides a faster delivery service. Commonly used in VoIP, real-time video, etc.

Protocol Analyzer

A diagnostic software that can examine and display data packets that are being transmitted over a network. It can examine packets from protocols that operate on the first four layers of the OSI model.

The TCP/IP Model

A four-layer model developed by the United States Department of Defense. To some extent, it is similar to the OSI model.

Internet Group Management Protocol (IGMP)

A protocol in the TCP/IP suite that supports multicasting in a routed environment. Operating at Layer 3 of the ISO model, it provides one-to-many communications and is used to inform all systems on the network as to what host currently belongs to which multicast group.

Three-Way Handshake

TCP uses this method to establish a connection. Before a client attempts to connect with a server, the server must perform a passive open. The server binds to and listens at a port to open it up for connections. Once the passive open is established, a client may initiate an active open. To establish a connection, this occurs: SYN, SYN-ACK, ACK.

(TCP/IP Model) Transport Layer

The TCP/IP protocol suite includes two protocols at this layer of the TCP/IP Model: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). These protocols correspond to Layer 4 of the OSI model.

Connection-Oriented Protocols

These protocols are a data transmission method in which a connection is established before any data can be sent, and where a stream of data is delivered in the same order as it was sent. TCP is an example of a transport protocol of this nature.

Connectionless Protocols

These protocols are a data transmission method that does not establish a connection between devices and where data may be delivered out of order and may be delivered over different paths. UDP is an example of a transport protocol of this nature.

Address Resolution Protocol (ARP)

This protocol maps an IP address to a physical (MAC) address recognized within a local network. This protocol enables you to dynamically discover the mapping of a Layer 3 IP address to a Layer 2 MAC address. The protocol resides on Layer 2 of the OSI model.

Internet Control Message Protocol (ICMP)

Used with IP, this protocol attempts to report on the condition of a connection between two nodes. If a node's buffers flood from receiving data too quickly, the receiving node sends an ____ source quench message to slow down data transmission. When you ping from one device to another, you are using this protocol.