TCP/IP vs OSI : OSI(Open System Interconnection) TCP/IP (Transmission Control Protocol / Internet Protocol) Theoretical model Model around which internet is build Has 7 architecture layers Has 4   architecture layers Protocol in-dependent standard Protocol dependent standard Developed by ISO (International Standard Organization) Developed by Department of Defense   (DoD) OSI model has a separate Application Layer, Presentation layer and Session layer. TCP/IP has only application layer which initiates the process, defines the format and create, maintain and terminate the session. Network Layer is both Connection Oriented and Connection less. Network Layer is Connection less. Transport Layer is Connection Oriented Transport Layer is both Connection Oriented and Connection less.          Diagrammatic Comparison between OSI Reference Model and TCP/IP Refere

TCP/IP Protocol Suite: Ø   Model around which internet is developed. Ø   Has four architecture layers Ø   Protocol-dependant standard Ø   Theoretical we learn OSI but when it comes to practical implementation , we use TCP/IP protocol suite. Ø     TCP/IP is a hierarchical protocol . The term hierarchical means that each upper-level protocol is supported by one or more lower-level protocols. Physical and Data Link Layers Ø   At the physical and data link layers, TCP/IP does not define any specific protocol. A network in a TCP/IP internetwork can be a local-area network or a wide-area network . Network Layer Ø   At the network layer ,TCP/IP supports IP which uses four supporting protocols: ARP, RARP, ICMP, and IGMP. Internetworking Protocol (IP) Ø   IP is an unreliable and connectionless protocol which does not   provide error checking or tracking. IP transports data in packets called datagrams Address Resolution Protocol Ø   ARP is used to f

Ø   Physical layer deals with physical transmission of binary data on a given media (Copper, Fiber, Wireless….etc) Ø   Devices work at physical layer are Hub, Modems, Repeaters and transmission media The physical layer is also concerned with the following: 1. Physical characteristics of interfaces and medium: •      The physical layer defines the characteristics of the interface between the devices and the transmission medium. •      It also defines the type of transmission medium 2. Representation   of   bits: •      The physical    layer data    consists    of a    stream   of bits (sequence   of Os   or   1s)   with no   interpretation.   •      To   be   transmitted,   bits   must be encoded into signals electrical or optical . The physical layer defines the type of encoding (how Os and Is are changed to signals). 3. Data rate/ Transmission rate: •      The number of bits sent each second -is also defined by the physical layer. •      In

Ø   Data Link Layer is responsible for end-to-end delivery of frames between devices on a LAN Network segment Ø   Data link layer comprises of two sub-layers ·      Logical Link Control:  It deals with protocols, flow-control, and error control ·      Media Access Control:  It deals with actual control of media Ø   It deals with hardware addresses (MAC addresses) Ø   Devices work at Data Link layer are “Switches” Ø   Data Link Layer is second layer of OSI Layered Model . Ø   Data link layer hides the details of underlying hardware and represents itself to upper layer as the medium to communicate. Ø   Data link layer works between two hosts which are directly connected in some sense . This direct connection could be point to point or broadcast. Ø   Data link layer is responsible for converting data stream to signals bit by bit and to send that over the underlying hardware. Ø   At the receiving end , Data link layer picks up data from hardware which are i