CSE 313 Data Communication Lec 01 Sabbir Muhammad Saleh

Textbook Data Communications and Networking (Fifth Edition). Behrouz Forouzan. You may also refer books of your choice with similar content or better readability. You can share you experience with the rest of the class.

Course Grading Outline Attendance: 10% Assignment: 10% Class Test: 10% Midterm:30% Final:40%

TCP/IP Stack (Protocol suite)

The Application Layer The Application Layer (Layer 4): The Application layer of the TCP/IP model is consider to be compatible with the application, presentation, and session layer of the OSI reference model. This layer gives facility to the applications for accessing the networking services. This is the fourth (4th) layer of TCP/IP model. It consists of high level protocols. This layer has ability to utilize both protocols TCP and UDP. For e.g. TFTP (trivial FTP) uses UDP because usually on a LAN the physical links are sufficiently small to make sure rapid and reliable packet transportation without errors. SMTP instead uses TCP due to error checking abilities.

The Transport Layer The Transport Layer (Layer 3): The Transport layer is the third (3rd) layer of the TCP/IP model. It transports the services which being used by the application layer. The Transport layer is similar like the transport layer of the OSI reference model and performs the same functions, like it uses both TCP and UDP protocols. Error detection and recovery also process at this layer. The transport layer also uses checksums, acknowledgements, and timeouts for controlling transmissions and end to end assured delivery.  Unlike the OSI reference model, TCP/IP model handles reliability of end-to-end issues.

The Internet Layer The Internet Layer (Layer 2): The Internet layer of the TCP/IP model performs the responsibilities as same like the Network layer of the OSI reference model. So, data delivery, key component of this architecture and routing is the main accountability of this layer. The Internet layer permits the transmission across the networks of multiple kinds and allows translation between dissimilar data addressing schemes.

The Internet Layer This layer allows packets to travel to the same destination via multiple paths. The packets may be received out of order because the way through to the desired network is not predestined. In this second (2nd) layer of the TCP/IP model, the main protocols are IP and ARP.

The Network Access Layer Network Access Layer (Layer 1): The Network Access layer is the first (1st) layer of the Transmission Control Protocol/Internet Protocol (TCP/IP) model. The Data Link layer and the Physical layer of the Open System Interconnection (OSI) Reference model, which consists of real hardware, are combined in this layer. The Network Access layer contains of wires, network interface cards (NICs), other transmission media, connectors, wireless, signal strength, wavelength, etc. along with many others.

The Network Access Layer This layer executes the different LAN operating algorithms, such as Carrier Sense Multiple Access with Collision Detection (CSMA/CD), etc. And data placement in a frame also happens in this layer. The frame format is dependent on the system being used. The frame carries data, hardware address of the host and information for data integrity.

Address Types in TCP/IP Stack Four levels of addresses are used in an internet employing the TCP/IP protocols: Physical (link) addresses Logical (IP) addresses Port addresses Specific addresses

Address Types in TCP/IP Stack

Relationship of Layers and Addresses