osi and tci-ip model
TRANSCRIPT
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OSI Model & TCP/IP
Chapter 2
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OSI LayersOSI Model
Data unit Layer Function
Host
layers
Data
7. Application Network process to application
6. PresentationData representation,encryption and decryption
5. Session Interhost communicationSegments
4. TransportEnd-to-end connections andreliability, Flow control
Medialayers
Packet 3. NetworkPath determination and logicaladdressing
Frame 2. Data Link Physical addressing
Bit 1. PhysicalMedia, signal and binarytransmission
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Going from layer 1 to 7: Please Do Not Throw Sausage PizzaAway
Going from layer 7 to 1: All People Seem To Need DataProcessing
http://en.wikipedia.org/wiki/Application_Layerhttp://en.wikipedia.org/wiki/Presentation_Layerhttp://en.wikipedia.org/wiki/Session_Layerhttp://en.wikipedia.org/wiki/Transport_Layerhttp://en.wikipedia.org/wiki/Network_Layerhttp://en.wikipedia.org/wiki/Logical_addresshttp://en.wikipedia.org/wiki/Logical_addresshttp://en.wikipedia.org/wiki/Data_Link_Layerhttp://en.wikipedia.org/wiki/Physical_Layerhttp://en.wikipedia.org/wiki/Physical_Layerhttp://en.wikipedia.org/wiki/Data_Link_Layerhttp://en.wikipedia.org/wiki/Logical_addresshttp://en.wikipedia.org/wiki/Logical_addresshttp://en.wikipedia.org/wiki/Network_Layerhttp://en.wikipedia.org/wiki/Transport_Layerhttp://en.wikipedia.org/wiki/Session_Layerhttp://en.wikipedia.org/wiki/Presentation_Layerhttp://en.wikipedia.org/wiki/Application_Layer -
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Layer1: Physical Layer
The physical layer deals with the physicalcharacteristics of the transmission medium.
It defines the electrical, mechanical, procedural,and functional specifications for activating,
maintaining, and deactivating the physical linkbetween end systems.
Such characteristics as voltage levels, timing ofvoltage changes, physical data rates, maximum
transmission distances, physical connectors, andother similar attributes are defined by physicallayer specifications.
Examples :- EIA/TIA-232, RJ45, NRZ.
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Layer 2: Data Link Layer
The data link layer provides access to thenetworking media and physicaltransmission across the media and thisenables the data to locate its intendeddestination on a network.
The data link layer provides reliable transitof data across a physical link by using the
Media Access Control (MAC) addresses. The data link layer uses the MAC address
to define a hardware or data link address in
order for multiple stations to share the samemedium and still uni uel identif each 5
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Layer 2: Data Link Layer
Another is Logical Link Control (LLC).provides data transmission method indifferent network. It will re-package
date and add a new header. Concerned with network topology,
network access, error notification,ordered delivery of frames, and flowcontrol.
Examples :- Ethernet, Frame Relay,FDDI
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Layer 3: Network Layer
The Network Layer performs network routing functions,
perform fragmentation and reassembly,
report delivery errors.
The network layer also defines how tofragment a packet into smaller packets
to accommodate different media. Routers operate at Layer 3.
Protocols examples :- IP, IPX,
AppleTalk. 7
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Layer 4: Transport Layer
The Transport Layer provides transparenttransfer of data between end users,providing reliable data transfer services tothe upper layers.
The Transport Layer controls the reliabilityof a given link through flow control,segmentation/de-segmentation, and error
control. Layer 4 protocols include TCP
(Transmission Control Protocol) and UDP(User Datagram Protocol).
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Layer 5: Session Layer
The session layer defines how to start, control andend conversations (called sessions) betweenapplications.
This includes the control and management of
multiple bi-directional messages using dialoguecontrol.
It also synchronizes dialogue between two hosts'presentation layers and manages their data
exchange. The session layer offers provisions for efficient data
transfer.
Examples :- SQL, ASP(AppleTalk Session
Protocol). 9
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Layer 6: Presentation Layer
It is sometimes called the syntax layer.
The presentation layer ensures that the informationthat the application layer of one system sends outis readable by the application layer of anothersystem.
If necessary, the presentation layer translatesbetween multiple data formats by using a commonformat.
Provides encryption and compression of data.
Examples :- JPEG, MPEG, ASCII, EBCDIC, HTML.
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Layer 7: Application Layer
The application layer is the OSI layerthat is closest to the user.
It provides network services to the
users applications.
It differs from the other layers in that itdoes not provide services to any other
OSI layer, but rather, only toapplications outside the OSI model.
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Layer 7: Application Layer
Examples of such applications arespreadsheet programs, word processingprograms, and bank terminal programs.
Some examples of application layerimplementations include
Hypertext Transfer Protocol (HTTP)
File Transfer Protocol (FTP) Simple Mail Transfer Protocol (SMTP)
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Introduction TCP/IP
The Internet Protocol Suite (commonlyknown as TCP/IP) is the setof communications protocols used for
the Internet and other similar networks. It is named from two of the most
important protocols in it:
the Transmission Control Protocol (TCP) and
the Internet Protocol (IP), which were the firsttwo networking protocols defined in thisstandard.
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TCP/IP Layers
OSI TCP/IP
Application LayerApplication Layer
TELNET, FTP, SMTP, POP3, SNMP,
NNTP, DNS,NIS, NFS, HTTP, ...Presentation Layer
Session Layer
Transport Layer Transport LayerTCP , UDP , ...
Network Layer Internet LayerIP , ICMP, ARP, RARP, ...
Data Link Layer Link LayerFDDI, Ethernet, ISDN, X.25,...
Physical Layer
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TCP/IP Some Protocol
Layer Protocol
Application
DNS, TFTP, TLS/SSL, FTP, Gopher, HTTP, IMAP, IRC, NNTP, POP3, SIP, SMTP, SMPP, SNMP, SSH, Telnet, Echo, RTP, PNRP, rlogin, ENRP
Routing protocols like BGP and RIP which run over TCP/UDP, mayalso be considered part of the Internet Layer.
Transport TCP, UDP, DCCP, SCTP, IL, RUDP, RSVP
Internet
IP (IPv4, IPv6), ICMP, IGMP, and ICMPv6
OSPF for IPv4 was initially considered IP layer protocol since itruns per IP-subnet, but has been placed on the Link since RFC2740.
Link ARP, RARP, OSPF (IPv4/IPv6), IS-IS, NDP
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http://en.wikipedia.org/wiki/Application_layerhttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocolhttp://en.wikipedia.org/wiki/Transport_Layer_Securityhttp://en.wikipedia.org/wiki/File_Transfer_Protocolhttp://en.wikipedia.org/wiki/Gopher_(protocol)http://en.wikipedia.org/wiki/HyperText_Transfer_Protocolhttp://en.wikipedia.org/wiki/Internet_Message_Access_Protocolhttp://en.wikipedia.org/wiki/Internet_Relay_Chathttp://en.wikipedia.org/wiki/Network_News_Transfer_Protocolhttp://en.wikipedia.org/wiki/Post_Office_Protocolhttp://en.wikipedia.org/wiki/Post_Office_Protocolhttp://en.wikipedia.org/wiki/Session_Initiation_Protocolhttp://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocolhttp://en.wikipedia.org/wiki/Short_message_peer-to-peer_protocolhttp://en.wikipedia.org/wiki/Simple_Network_Management_Protocolhttp://en.wikipedia.org/wiki/Secure_Shellhttp://en.wikipedia.org/wiki/Telnethttp://en.wikipedia.org/wiki/Echo_protocolhttp://en.wikipedia.org/wiki/Real-time_Transport_Protocolhttp://en.wikipedia.org/wiki/Peer_Name_Resolution_Protocolhttp://en.wikipedia.org/wiki/Rloginhttp://en.wikipedia.org/wiki/Rloginhttp://en.wikipedia.org/w/index.php?title=Endpoint_Handle_space_Redundancy_Protocol&action=edit&redlink=1http://en.wikipedia.org/wiki/Border_Gateway_Protocolhttp://en.wikipedia.org/wiki/Routing_Information_Protocolhttp://en.wikipedia.org/wiki/Transport_layerhttp://en.wikipedia.org/wiki/Transmission_Control_Protocolhttp://en.wikipedia.org/wiki/User_Datagram_Protocolhttp://en.wikipedia.org/wiki/Datagram_Congestion_Control_Protocolhttp://en.wikipedia.org/wiki/Stream_Control_Transmission_Protocolhttp://en.wikipedia.org/wiki/IL_Protocolhttp://en.wikipedia.org/wiki/Reliable_User_Datagram_Protocolhttp://en.wikipedia.org/wiki/Resource_reservation_protocolhttp://en.wikipedia.org/wiki/Internet_Layerhttp://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/IPv4http://en.wikipedia.org/wiki/IPv6http://en.wikipedia.org/wiki/Internet_Control_Message_Protocolhttp://en.wikipedia.org/wiki/Internet_Group_Management_Protocolhttp://en.wikipedia.org/wiki/ICMPv6http://en.wikipedia.org/wiki/Open_shortest_path_firsthttp://tools.ietf.org/html/rfc2740http://tools.ietf.org/html/rfc2740http://en.wikipedia.org/wiki/Link_Layerhttp://en.wikipedia.org/wiki/Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Reverse_Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Open_shortest_path_firsthttp://en.wikipedia.org/wiki/IS-IShttp://en.wikipedia.org/wiki/Neighbor_Discovery_Protocolhttp://en.wikipedia.org/wiki/Neighbor_Discovery_Protocolhttp://en.wikipedia.org/wiki/IS-IShttp://en.wikipedia.org/wiki/IS-IShttp://en.wikipedia.org/wiki/IS-IShttp://en.wikipedia.org/wiki/Open_shortest_path_firsthttp://en.wikipedia.org/wiki/Reverse_Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Address_Resolution_Protocolhttp://en.wikipedia.org/wiki/Link_Layerhttp://tools.ietf.org/html/rfc2740http://tools.ietf.org/html/rfc2740http://en.wikipedia.org/wiki/Open_shortest_path_firsthttp://en.wikipedia.org/wiki/ICMPv6http://en.wikipedia.org/wiki/Internet_Group_Management_Protocolhttp://en.wikipedia.org/wiki/Internet_Control_Message_Protocolhttp://en.wikipedia.org/wiki/IPv6http://en.wikipedia.org/wiki/IPv4http://en.wikipedia.org/wiki/Internet_Protocolhttp://en.wikipedia.org/wiki/Internet_Layerhttp://en.wikipedia.org/wiki/Resource_reservation_protocolhttp://en.wikipedia.org/wiki/Reliable_User_Datagram_Protocolhttp://en.wikipedia.org/wiki/IL_Protocolhttp://en.wikipedia.org/wiki/Stream_Control_Transmission_Protocolhttp://en.wikipedia.org/wiki/Datagram_Congestion_Control_Protocolhttp://en.wikipedia.org/wiki/User_Datagram_Protocolhttp://en.wikipedia.org/wiki/Transmission_Control_Protocolhttp://en.wikipedia.org/wiki/Transport_layerhttp://en.wikipedia.org/wiki/Routing_Information_Protocolhttp://en.wikipedia.org/wiki/Border_Gateway_Protocolhttp://en.wikipedia.org/w/index.php?title=Endpoint_Handle_space_Redundancy_Protocol&action=edit&redlink=1http://en.wikipedia.org/wiki/Rloginhttp://en.wikipedia.org/wiki/Rloginhttp://en.wikipedia.org/wiki/Peer_Name_Resolution_Protocolhttp://en.wikipedia.org/wiki/Real-time_Transport_Protocolhttp://en.wikipedia.org/wiki/Echo_protocolhttp://en.wikipedia.org/wiki/Telnethttp://en.wikipedia.org/wiki/Secure_Shellhttp://en.wikipedia.org/wiki/Simple_Network_Management_Protocolhttp://en.wikipedia.org/wiki/Short_message_peer-to-peer_protocolhttp://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocolhttp://en.wikipedia.org/wiki/Session_Initiation_Protocolhttp://en.wikipedia.org/wiki/Post_Office_Protocolhttp://en.wikipedia.org/wiki/Post_Office_Protocolhttp://en.wikipedia.org/wiki/Network_News_Transfer_Protocolhttp://en.wikipedia.org/wiki/Internet_Relay_Chathttp://en.wikipedia.org/wiki/Internet_Message_Access_Protocolhttp://en.wikipedia.org/wiki/HyperText_Transfer_Protocolhttp://en.wikipedia.org/wiki/Gopher_(protocol)http://en.wikipedia.org/wiki/File_Transfer_Protocolhttp://en.wikipedia.org/wiki/Transport_Layer_Securityhttp://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocolhttp://en.wikipedia.org/wiki/Domain_Name_Systemhttp://en.wikipedia.org/wiki/Application_layer 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Connecting Below Internet Level
Hub Center of star topology
In Ethernet, multiportrepeater or concentrator
Bridge Connects 2 networks of
same technologyextended LAN
Filters/forwards/floodsbased on MAC
Link layer - frames
Switch Connects 2+ networks
packet-switched network
Reduces collisions
Ethernet Ethernet
Hub
Bridge
Switch
Ethernet Ethernet
CISCOSYSTEMS
CISCOS YSTEMS CISCOS YSTEMS
T3 STS-N
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Connecting at the Internet Level
Router
Originally gateway
Forwards packets
based on network layerinfo (IP)
Separate broadcastdomains
In each domain, IPpacket encapsulated indomain-specific packet
Token-ring
CISCOSYST EMS
Ethernet
CISCOSYST EMS
Ethernet
CISCOSYST EMS
Router