Wireless Network Homework 1

tags: Wireless Network

Student ID : 410921317
Name : Thanongsak Khumpa

Official link of the report

https://hackmd.io/@Lince/S1WOtT5Xo

Hypertext Transfer Protocol (HTTP)

is an application-layer protocol for transmitting hypermedia documents, such as HTML. It was designed for communication between web browsers and web servers, but it can also be used for other purposes. HTTP follows a classical client-server model, with a client opening a connection to make a request, then waiting until it receives a response. HTTP is a stateless protocol, meaning that the server does not keep any data (state) between two requests. Transmission Control Protocol (TCP)

TCP (Transmission Control Protocol)

is a Transport Layer host-to-host protocol for connection-oriented communication between two computers on an IP network. TCP uses virtual ports to create a virtual end-to-end connection that can reuse the physical connections between two computers. TCP encapsulates higher level protocol data such as HTTP and, SMTP (email).

UDP (User Datagram Protocol)

is a long-standing protocol used together with IP for sending data when transmission speed and efficiency matter more than security and reliability.
UDP uses a simple connectionless communication model with a minimum of protocol mechanism. UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; There is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an application may use the Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP) which are designed for this purpose.
UDP is suitable for purposes where error checking and correction are either not necessary or are performed in the application; UDP avoids the overhead of such processing in the protocol stack. Time-sensitive applications often use UDP because dropping packets is preferable to waiting for packets delayed due to etransmission, which may not be an option in a real-time system.

IP (Internet Protocol)

provides unreliable, connectionless packet delivery for the Internet. IP is connectionless because it treats each packet of information independently. It is unreliable because it does not guarantee delivery, meaning, it does not require acknowledgments from the sending host, the receiving host, or intermediate hosts.
IP provides the interface to the network interface level protocols. The physical connections of a network transfer information in a frame with a header and data. The header contains the source address and the destination address. IP uses an Internet datagram that contains information similar to the physical frame. The datagram also has a header ontaining Internet Protocol addresses of both source and destination of the data. IP defines the format of all the data sent over the Internet.

IPX (Internetwork Packet Exchange)

is a set of acketswitching and packet-sequencing protocols designed to function in small and large networks. In the OSI model, IPX is the network layer protocol in the Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) protocol stack, which is primarily used on Novell Netware operating systems.
PX follows a layered structure of protocols. These layers allow applications to control the application layer, presentation, and session layer. Each layer services the layer above it and is provided by the layer below it.
IPX/SPX is similar to TCP/IP and other Internet protocols, but IPX/SPX was designed as a TCP/IP alternative. IPX/SPX is ideal for local area networks or private networks with different protocol and communication functions. Like IP, IPX is connectionless and contains end user data, such as IP and network addresses. SPX is connectionoriented and is used for connection-related functions and data routing.

UPNP (Universal Plug and Play)

is a service that allows devices on the same local network to discover each other and automatically connect through standard networking protocols (such as TCP/IP HTTP, and DHCP). Some examples of UPnP devices are printers, gaming consoles, WiFi devices, IP cameras, routers, mobile devices, and Smart TVs.
UPnP can also modify router settings to open ports into a firewall to facilitate the connection of devices outside of a network.
This service reduces the complexity of networking devices by automatically forwarding router ports to new devices, removing the hassle of manual forwarding. But this convenience could come at significant security risks.

DNS (Domain Name System)

is a hierarchical and decentralized naming system for Internet connected resources. DNS maintains a list of domain names along with the resources,such as IP addresses, that are associated with them.
The most prominent function of DNS is the translation of human-friendly domain names (such as mozilla.org) to a numeric IP address (such as 151.106.5.172); this process of mapping a domain name to the appropriate IP address is known as a DNS lookup. By contrast, a reverse DNS lookup (rDNS) is used to determine the domain name associated with an IP address

DHCP (Dynamic Host Configuration Protocol)

is a client/server protocol that automatically provides an Internet Protocol (IP) host with its IP address and other related configuration information such as the subnet mask and default gateway. RFCs 2131 and 2132 define DHCP as an Internet Engineering Task Force (IETF) standard based on Bootstrap Protocol (BOOTP), a protocol with which DHCP shares many implementation details. DHCP allows hosts to obtain required TCP/IP configuration information from a DHCP server. Every device on a TCP/IP-based network must have a unique unicast IP address to access the network and its resources. Without DHCP, IP addresses for new computers or computers that are moved from one subnet to another must be configured manually; IP addresses for computers that are removed from the network must be manually reclaimed.

ICMP (The Internet Control Message Protocol)

is a network layer protocol used by network devices to diagnose network communication issues. ICMP is mainly used to determine whether or not data is reaching its intended destination in a timely manner. Commonly, the ICMP protocol is used on network devices, such as routers. ICMP is crucial for error reporting and testing, but it can also be used in distributed denial-of-service (DDoS) attacks.
ICMP is not associated with a transport layer protocol such as TCP or UDP. This makes ICMP a connectionless protocol: one device does not need to open a connection with another device before sending an ICMP message. Normal IP traffic is sent using TCP, which means any two devices that exchange data will first carry out a TCP handshake to ensure both devices are ready to receive data. ICMP does not open a connection in this way. The ICMP protocol also does not allow for targeting a specific port on a device.

FTP (File Transfer Protocol)

is an insecure protocol for transferring files from one host to another over the Internet. For many years it was the de facto standard way of transferring files, but as it is inherently insecure, it is no longer supported by many hosting accounts. Instead, you should use SFTP (a secure, encrypted version of FTP) or another secure method for transferring files like Rsync over SSH.

PPPOE (Point-to-Point Protocol over Ethernet)

combines PPP, which typically runs over broadband connections, with the Ethernet link-layer protocol that allows users to connect to a network of hosts over a bridge or access concentrator. PPPoE enables service providers to maintain access control through PPP connections and also manage multiple hosts at a remote site.
PPPoE connects multiple hosts on an Ethernet LAN to a remote site through a single customer premises equipment (CPE) device—a Juniper Networks device. Hosts share a common digital subscriber line (DSL), a cable modem, or a wireless connection to the Internet.

NAT (Network Address Translation)

is a technique for letting multiple computers share an IP address. NAT assigns unique addresses to each computer on the local network and adjusts incoming/outgoing network traffic to send data to the right place.

SMTP (Simple Mail Transfer Protocol)

is a TCP/IP protocol used in sending and receiving e-mail. However, since it is limited in its ability to queue essages at the receiving end, it is usually used with one of two other protocols, POP3 (Post Office Protocol) or IMAP (Internet Message Access Protocol), that let the user save messages in a server mailbox and download them periodically from the server. In other words, users typically use a program that uses SMTP for sending e-mail and either POP3 or IMAP for receiving e-mail.