TCP IP Internet Protocol Suite and OSI Model Layers

OSI stands for Open System Interconnection (Internet protocol suite) is a reference model and it conjointly web protocol suite that describes seven layers that laptop systems use to speak over a network. it had been the primary normal model for network communications, adopted by all major laptop and telecommunication corporations within the early Nineteen Eighties.

The fashionable web isn’t supported OSI, however on the less complicated TCP/IP model. However, the OSI 7-layer model remains wide used, because it helps visualize and communicate however networks operate, and helps isolate and troubleshoot networking issues.

OSI was introduced in 1983 by representatives of the foremost laptop and medium corporations, and was adopted by ISO as a global normal in 1984. source

OSI Model Layers:

No	Layer	Function	Unit	Protocols/Services	Devices
7	Application	network application services and processes	data	FTP, TFTP, HTTP, SMTP, SMB, NCP, Telnet, NTP, File & Print, DNS	gateway
6	Presentation	encryption, formatting, compression, translation	data	ASCII, JPEG, GIF, TIFF, MIDI, MPEG, MIME, Quicktime	gateway
5	Session	establishes maintains, manages network connections and sessions	data	RPC, ZIP, SCP, SQL, NetBIOS, NFS, ASP, LDAP, SSL, SMB	gateway
4	Transport	end-end error recovery, connectivity, flow control	segments	TCP, SPX, UDP, NBP, NCP. NetBEUI, SCTP	gateway
3	Network	routing, forwarding of packets; sequencing of datagram	packets	IP, IPX, ARP, RARP, DHCP, BootP, ICMP, RIP, BGP, OSPF, IPSec	router, brouter
2	Data Link	encoding/decoding of packets into bits; frame synchronization, error checking	frames	MAC, LLC, PPP, ATM, frame relay, 802.11b/g, L2TP, FDDI	switch, bridge
1	Physical	electrical, mechanical, lightwave, radio frequency, media specifications	bits	Ethernet, WiFi, Token Ring, BRI, RS232, V.35	hub, NIC, WAP

TCP/IP Model Layers:

The OSI Model we simply checked out is simply a reference/logical model. it internet protocol suite had been designed to explain the functions of the communication system by dividing the communication procedure into smaller and less complicated parts. however once we name the TCP/IP model, it had been designed and developed by Department of Defense (DoD) in Sixties and is predicated on normal protocols. It internet protocol suite stands for Transmission management Protocol/Internet Protocol or TCP science web Protocol Suite . The TCP/IP model is a elliptical version of the OSI model. It contains four layers, in contrast to seven layers within the OSI model. The layers are:

1. Network Access/Link Layer
2. Internet Layer
3. Host-to-Host/Transport Layer
4. Process/Application Layer

TCP science web Protocol Suite

TIC/UDP port	Protocol	Full Name	Description	OSI Layer
7	ICMP	Internet management Massage protocol	Used for error (echo)reporting,flow management and route testing	Network
20/21	FTP	File transfer protocol	Protocol for uploading and down-loading files to and from a far off host; conjointly accommodates basic file management tasks	Application
22	SSH	Secure Shell	Like Telnet permits sessions to be opened on a far off host, however provides authentication and encoding capabilities	Application
22 (work with SSH)	SFTP	Secure file Transfer Protocol	Protocol that performs the same operate to FTP, however Provides safer authentication and encoding  mechanisms	Application
22 (work with SSH)	SCP	Secure Copy Protocol	Protocol that uses Secure shell (SSH) Technology to supply a secure thanks to copy files between systems	Application
22 (work with SSH)	LDAP	Lightweight Directory Access Protocol	Provides a mechanism to access directory Services systems	Application
23	Telnet	Telnet	permits Sessions to be opened on a far off host	Application
25	SMTP	Simple Mail Transfer Protocol	Delivers emails between email servers; causation of emails; uses TCP	Application
465	SMTPs	Secure straightforward Mail Transfer Protocol	Delivers emails between email servers; causation of emails; uses TCP	Application
53	DNS	Domain Name System	Translates hostnames to science addresses; uses TCP (zone transfers), UDP (queries	Application
69	TFTP	Trivial file Transfer protocol	Mechanism for transporting email across networks	Application
80	HTTP	Hypertext Transfer protocol	Protocol for retrieving files from an internet server.	Application
109	POP2	Post workplace Protocol – Version 2	Used for retrieving email from a server on that the mail is stored	Application
110/143	POP3/IMAP4	Post workplace Protocol version 3/ web Message Access Protocol Version 4	Used for retrieving email from a server on that the mail is stored	Application
995/993	POP3s/IMAP4s	Post workplace Protocol version 3/ web Message Access Protocol Version 4	Used for retrieving email from a server on that the mail is stored	Application
119	NNTP	Network News transport Protocol	Protocol used for accessing and downloading messages from Internet-based newsgroups.	Application
123	NTP	Network Time Protocol	Used to communication time synchronization data between devices	Application
443	HTTPS	Hypertext Transfer protocol Secure	Secure Protocol for retrieving files from an internet server.	Application
515	LPR	Line printer remote	Provides a mechanism to send printing tasks to a print server	Application
	IP	Internet Protocol	Connectionless protocol used for moving knowledge around a network.	Network
	TCP	Transmission management Protocol	Connection-oriented protocol that provides flow management, sequencing, and retransmission of born packets	Transport
	UDP	User datagram protocol	Connectionless various to TCP that’s used for application that don’t need the functions offered by TCP	Application
	ARP	Address Resolution Protocol	Resolves science addresses to mack addresses, to alter communication between devices	Network
	RARP	Reverse Address Resolution Protocol	Resolves mack addresses to science addresses	Network
	IGMP	Internet cluster Management protocol	Protocol used for communication between devices associate degree exceedingly|in a very} multicast group	Network
	ICS	Internet association Sharing	Connects multiple laptops on an area network to the net through one association ANd science address; uses NAT	Network
	WINS	Windows web Naming Service	Resolves a number NetBIOS name or computer name into an science address; utilized in bequest Windows	Application
	Zeroconf	Zero Configuration	Connects networking devices exploitation an LAN cable; no configuration or DHCP required	Application
	SMB	Server Message Block	Shares files, directories, ANd services; message format utilized by DOS; permits UNIX system/Linux and Windows machines to share files	Application
	Samba	–	Provides file and print services to SMB clients; runs on UNIX system and Linux	Application
	ICA	Independent Computing Architecture	The core of Citrix presentation server that allows Windows or UNIX server to run an application for multiple users simultaneously
	Apache	–	A standard property right UNIX-based net server	Application
	AFP	Appletalk File Protocol	A file sharing protocol used with TCP/IP to allow non-apple computers to access apple servers

Remote access protocols and services

Name	Meaning	Function
RAS	Remote Access Service	Used for client remote access to a network
PPP	Point-Point Protocol	Used to establish an internet connection between serial point-to-point links; provides for dial-up connnections to networks
SLIP	Serial Line Internet Protocol	Used to connect to the internet via a dial-up modem; older, slower, less reliable than PPP
PPPoE	PPP over Ethernet	Uses PPP over Ethernet to connect an ethernet LAN user to the internet using an ADSL or cable modem; users share a broadband connection
PPTP	Point-Point Tunnel Protocol	A form of encryption that provides a tunnel for secure connections over the internet; used to create VPN
VPN	Virtual Private Network	A private, secure, point to point connection from a company LAN to the remote users and wireless nodes using the internet
RDP	Remote Desktop Protocol	connects a client to a network via a terminal server and uses authentication to establish connection to run applications and printers remotely

Security protocols

Name	Meaning	Function
IPSec	Internet Protocol Security	Provides authentication and encryption over the internet; works with IPv4 and IPv6; used to secure VPN
L2TP	Layer 2 Tunneling Protocol	Supports non-TCP/IP protocols VPN over the internet; combines the best features of PPTP and L2F
SSL	Secure Sockets Layer	Uses a private key to encrypt data that is transferred over the SSL connection; service independent and can secure different network applications
WEP	Wired Equivalent Privacy	Encrypts and protects data packets over radio frequencies; does not offer end-end security
WPA	WiFi Protected Access	Offers improved data encryption and user authentication using the wireless devices MAC address; uses TKIP encryption
AES	Advanced Encryption Standard	A cryptographic cipher that uses Rijndael algorithm
PGP	Pretty Good Privacy	An encryption utility based on public key encryption designed to encrypt email transmissions
802.1x	–	Method for passing EAP over both wired and wireless networks; provides authentication services for wireless networks not using PPP

Authentication protocols

Name		Function
CHAP	Challenge Handshake Authentication Protocol	Uses a hashed algorithm MD5 that provides client response encryption; weak and one-way authentication protocol
MS-CHAP	Microsoft Challenge Handshake Authentication Protocol	Has two versions used in Windows systems that offers more security; version1 not compatible with version2
PAP	Password Authentication Protocol	The weakest authentication protocol that sends username and password in clear text over the network to be verified by RAS
RADIUS	Remote Authentication Dial-in User Service	An industry standard that provides authentication, authorization, and accounting services
Kerberos	–	A fully-fledge security system that uses secret key cryptography
EAP	Extensible Authentication Protocol	A general protocol often used by a wireless devices to connect to a RADIUS server; TLS uses certificates such as smart cards

Routing protocols

Name	Meaning	Function
RIP	Routing Information Protocol	Finds the quickest route between two computers; offers a maximum of 16 hops between routers before deciding that a packet is undeliverable
OSPF	Open Shortest Path First	A descendant of RIP that increases its speed and reliability; much used on the internet; accepts 256 hops between routers
IGRP	Interior Gateway Routing Protocol	A propriety protocol from Cisco that takes bandwidth, latency, reliability, and current traffic load into consideration
EGP	Exterior Gateway Protocol	A distance vector protocol that uses polling to retrieve routing information
BGP	Border Gateway Protocol	Used to span autonomous systems in the internet; used at the edge of networks; designed to supersede EGP
NLSP	Netware Link Services Protocol	A link state routing protocol that was designed to reduce wasted bandwidth associated with RIP
RTMP	Routing Table Maintenance Protocol	Used by Appletalk to ensure that all routers in the network have consistent routing information