NETWORK SERVICES
Concept of Network
Transmission Control Protocol
Port Number
DNS
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks.
Its most important role is to provide an IP address for each host name, and a list of mail exchange servers that receive mail for each domain.
SMTP
SMTP is used to send and receive email. It is sometimes paired with IMAP or POP3 (for example, by a user-level application), which handles the retrieval of messages, while SMTP primarily sends messages to a server for forwarding. SMTP can both send and receive mail, but it's bad at queuing incoming messages, hence the common delegation to other protocols.
POP3
Post Office Protocol 3, or POP3, is the most commonly used protocol for receiving email over the internet. This standard protocol, which most email servers and their clients support, is used to receive emails from a remote server and send to a local client.
File Transfer Protocol
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data connections between the client and the server.
FTPS
FTPS (also known as FTP-SSL and FTP Secure) is an extension to the commonly used File Transfer Protocol (FTP) that adds support for the Transport Layer Security (TLS) and, formerly, the Secure Sockets Layer (SSL, which is now prohibited by RFC7568) cryptographic protocols.
SSH FTP
the SSH File Transfer Protocol (also known as Secure File Transfer Protocol or SFTP) is a network protocol that provides file access, file transfer, and file management over any reliable data stream.
Hypertext transfer protocol secure(HTTPS)
Hypertext transfer protocol secure (HTTPS) is the secure version of HTTP, which is the primary protocol used to send data between a web browser and a website. HTTPS is encrypted in order to increase security of data transfer.This is particularly important when users transmit sensitive data, such as by logging into a bank account, email service, or health insurance provider.
HTTP
The Hypertext Transfer Protocol (HTTP) is a networking protocol for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web. HTTP functions as a request-response protocol in the client-server computing model.
The basics of networking are simple; connecting two or more computers via wire or wireless.
It can facilitate users to share data at a fast and efficient rate. With the network as well, users can share hardware such as printers, scanners, fax machines and so on. With this, a large group or organization does not need to buy so much office equipment, just need to connect.
Networking is connecting computers to share information and resources. It is also a changing and very complex technology. A lot can be done to connect hardware such as printers, computers and others. It can also connect software from one computer to another.
Transmission Control Protocol (TCP) is one of the core protocols of the Internet Protocol Suite.
TCP is one of the two original components of the suite involved, completing the Internet Protocol (IP) and then the entire suite is usually referred to as TCP/IP.
TCP provides a direct data integrity exchange service between two network hosts, while IP handles the addressing and routing of messages across one or more networks. Specifically, TCP provides the orderly and robust transmission of a stream of bits from one program on one computer to another program on another computer. Most major Internet applications rely on TCP, including the World Wide Web, e-mail, and file transfer.
OSI Model
The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of [ISO] standards development for the purpose of systems interconnection'.
In the OSI reference model, the communications between a computing system are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
Data link layer
The data link layer is the second layer in the OSI model and the TCP/IP model of a data communication protocol in a computer network. The data link layer provides the means and procedures for establishing, maintaining, and releasing data lines between terminals and network nodes.
Media Access Control (MAC)
MAC may refer to the sublayer that determines who is allowed to access the media at any one time (e.g. CSMA/CD).
Logical Link Control (LLC)
The uppermost sublayer, LLC, multiplexes protocols running at the top of the data link layer, and optionally provides flow control, acknowledgment, and error notification.
network layer
The network layer provides the means of transferring variable-length network packets from a source to a destination host via one or more networks. Within the service layering semantics of the OSI network architecture, the network layer responds to service requests from the transport layer and issues service requests to the data link layer.
Physical layer
The physical layer is the first layer in the OSI model in a computer network. This layer transmits unstructured bit streams (unstructured raw bits) over physical media (such as network cables).
The physical layer will manage the mechanical and electrical specifications of the main connector, such as cables, connectors, and signaling options for the physical link between two nodes.
The physical layer determines how cables should be connected to the network interface card for example it determines how many pins the network card has and what the function of each pin is.
The physical layer sends zero and one bits (0 and 1) from one computer to another.
transport layer
the transport layer is a conceptual division of methods in the layered architecture of protocols in the network stack in the Internet protocol suite and the OSI model. The protocols of this layer provide end-to-end communication services for applications.
session layer
The session layer provides the mechanism for opening, closing and managing a session between end-user application processes, i.e., a semi-permanent dialogue. Communication sessions consist of requests and responses that occur between applications.
presentation layer
The presentation layer ensures the information that the application layer of one system sends out is readable by the application layer of another system. On the sending system it is responsible for conversion to standard, transmittable formats.[6] On the receiving system it is responsible for the translation, formatting, and delivery of information for processing or display.
application layer
application layer is an abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network.[1] An application layer abstraction is specified in both the Internet Protocol Suite (TCP/IP) and the OSI model.[2] Although both models use the same term for their respective highest-level layer, the detailed definitions and purposes are different.
application layer
application layer is an abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network.[1] An application layer abstraction is specified in both the Internet Protocol Suite (TCP/IP) and the OSI model.[2] Although both models use the same term for their respective highest-level layer, the detailed definitions and purposes are different.
transport layer
the transport layer is a conceptual division of methods in the layered architecture of protocols in the network stack in the Internet protocol suite and the OSI model. The protocols of this layer provide end-to-end communication services for applications.
The internet layer is a group of internetworking methods, protocols, and specifications in the Internet protocol suite that are used to transport network packets from the originating host across network boundaries; if necessary, to the destination host specified by an IP address. The internet layer derives its name from its function facilitating internetworking, which is the concept of connecting multiple networks with each other through gateways.
network layer
The network layer provides the means of transferring variable-length network packets from a source to a destination host via one or more networks. Within the service layering semantics of the OSI network architecture, the network layer responds to service requests from the transport layer and issues service requests to the data link layer.
