TCP/IP Protocol Stack: Architecture and Functionality
What is the TCP/IP Protocol Stack?
The TCP/IP protocol stack is a family or set of protocols covering the different levels of a modern network architecture.
Protocol: A set of standards to be met by regulated parties to understand each other.
Layer or level: To reduce the difficulty of communication, which is treated as one problem, it was decided to divide it into smaller, specialized subsets, resulting in different layers or levels of communication.
TCP/IP Architecture
The TCP/IP architecture is a family of protocols that cover all levels required for data transmission. It was introduced in 1973.
OSI Reference Model
The Open Systems Interconnection (OSI) Model was created by the ISO international standards organization. It was a theoretical study that defined the structure of a modern network architecture of seven layers, which in turn were divided into three large blocks.
Monolithic Communications Architecture
Monolithic communications architecture was an archaic communication architecture with a single layer that forced programmers to master all aspects of communication.
OSI Reference Model Process Blocks
Application Block
- Application Layer: The highest level of the hierarchy of layers, and the closest to the user. It welcomes network requests from all applications that require lower layers to use the network.
- Presentation Layer: Handles the semantics and syntax, i.e., the format of the data, to meet the specifications. In some cases, it applies a process of encoding/decoding and compression/decompression.
- Session Layer: Responsible for providing value-added services to the communication between sender and receiver, so we can better coordinate the dialogue between end users.
Transport Block
- Transport Layer: Responsible for controlling the flow of data in communication between the extremes. It is responsible for forwarding and receiving data to arrive without errors, sorted, and discarding duplicates.
Transmission Block
- Network Layer: Routes data toward its destination. It links and establishes a dialogue with the network to determine priorities and choose the best route to follow.
- Data Link Layer: Responsible for controlling the flow of data in communication between adjacent nodes that are physically interconnected, being a bridge between the source and destination equipment.
- Physical Layer: The layer that actually transforms the signals, since its main function is to convert bytes to the physical environment in bits to transmit and back.
The Sniffer Protocol Family
A sniffer is a program that monitors and analyzes network traffic to detect problems. It captures the data traffic of interest to know the efficiency of the network, and is also used to capture network data in an illegal form.
Address Resolution Protocol (ARP)
The ARP protocol is responsible for finding out the physical address of Medium Access Control, i.e., the MAC address of a card from an IP address. It is only valid if both teams are located on the same physical network.
Internet Message Control Protocol (IMCP)
The IMCP protocol allows your router or intermediate nodes to send control messages to hosts or computers that sent the information. On the Internet, there are no mechanisms to monitor and verify hardware connectivity, so it became necessary to implement this protocol, since the detection of faults and problems became complicated and difficult to control due to the lack of control mechanisms not provided by the IP protocol. Therefore, IMPC is the ideal complement to IP.
Broadcast and Multicast
Broadcast refers to all computers on a network. Multicast refers to a group of computers that have been signed to a particular service.
ICMP Protocol
The ICMP protocol is responsible for notifying the issuer in case of unexpected errors in any IP packet sent.
Internet Protocol (IP)
IP is in charge of data communication over a packet-switched network with no previous connection.
Transfer Control Protocol (TCP)
TCP is responsible for providing security to the communication. Because of the shortcomings discussed in the IP protocol, TCP is the one that will provide reliable and ordered service to the connection. The security of TCP makes it suitable for all critical services, where service reliability is essential.
User Datagram Protocol (UDP)
UDP is in charge of performing the functions of the transport layer, incorporating the mechanism of ports on its format message, but without applying any of the security measures that use TCP, since UDP is unreliable and provides no connection, and it adds no improvement in the quality of communication. Therefore, its use is more focused on speed and flexibility in communication.
TCP/IP Addresses
Public IP Addresses
Public IP addresses are visible (accessible) on the internet, and there cannot be two machines with the same public IP on the Internet. A computer with a public IP is accessible from any other Internet-connected computer.
Private IP Addresses
Private IP addresses are only accessed by other computers on the same intranet or extranet. Computers with private IP addresses can also connect to the Internet through a router that has a public IP assigned by an ISP.
Configuring TCP/IP for Windows 2000 Professional
Client configuration for Windows 2000 Professional is very simple. It is accessed through: Desktop Icon / My Network Places / Properties (right-click). Or through the path: Start / Settings / Control Panel / Network.