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Submit These Answers As A Single Word Document Apa Style Wit

Submit These Answers As A Single Word Document Apa Style Wit

1. Map the layers of the TCP/IP model to the OSI model.

The TCP/IP model, also known as the Internet protocol suite, consists of four layers: Application, Transport, Internet, and Network Access (or Link). The OSI model comprises seven layers: Application, Presentation, Session, Transport, Network, Data Link, and Physical. The mapping between these models is as follows:

  • Application Layer (TCP/IP) corresponds to the OSI Application, Presentation, and Session layers. These layers collectively manage high-level protocols, data representation, and sessions, which are primarily handled within the TCP/IP Application layer.
  • Transport Layer (TCP/UDP) of TCP/IP maps directly to the OSI Transport layer. Both provide end-to-end communication services such as reliable data transfer (TCP) or connectionless transmission (UDP).
  • Internet Layer (IP) aligns with the OSI Network layer. Both are responsible for logical addressing, routing, and packet forwarding.
  • Network Access Layer (Ethernet, Wi-Fi, etc.) represents the OSI Data Link and Physical layers. These are responsible for sending raw bits over the physical medium and managing protocol access to the physical network.

2. Each layer of OSI has a body/group that is responsible for the standards, please name them.

The standardization bodies responsible for each OSI layer are as follows:

  • Physical Layer: International Telecommunication Union - Telecommunication Standardization Sector (ITU-T)
  • Data Link Layer: IEEE (Institute of Electrical and Electronics Engineers), specifically the IEEE 802 working group
  • Network Layer: Internet Engineering Task Force (IETF), through protocols such as IP
  • Transport Layer: IETF, responsible for protocols such as TCP and UDP
  • Session Layer: ISO (International Organization for Standardization), via the ISO/IEC standards
  • Presentation Layer: ISO, with standards related to data formats, encryption, and compression
  • Application Layer: IETF and ISO, overseeing protocols like HTTP, FTP, SMTP, and DNS

3. Describe the progression through the OSI model of the following: - A web browser request and connection to - An email being sent from Outlook on a Windows machine from your APUS email account to [email protected]

Web Browser Request and Connection

When a user enters a website URL into a web browser, a multi-layered process occurs across the OSI model. First, at the Application layer, the user’s request is generated by the HTTP protocol, which is responsible for requesting web pages. The browser packages the request data, including headers and requested URL, and passes this data down to the Presentation layer, where it may be encrypted or formatted as necessary.

Next, the Session layer manages the session between the client (web browser) and server, establishing, maintaining, and terminating the connection. The data then proceeds to the Transport layer, where TCP (Transmission Control Protocol) segments the data into manageable packets, adding sequence numbers and error detection mechanisms to ensure reliable delivery.

The Internet layer then encapsulates these TCP segments within IP packets, assigning source and destination IP addresses, and determining the best route for data transmission. This data is then passed to the Data Link layer, which frames the packets for physical transmission over the network medium, such as Ethernet. It handles MAC addressing and access control. Finally, at the Physical layer, the bits are transmitted over the physical network medium—be it wired or wireless.

When the server receives the data, the process is reversed, with each layer removing its respective headers and managing data to establish the web page connection, ultimately delivering the requested content to the browser for display.

Email Sending from Outlook

Sending an email from Outlook involves a similar layer-by-layer process. The email message is created within the Outlook application at the Application layer, where SMTP (Simple Mail Transfer Protocol) or MAPI (Messaging Application Programming Interface) handles the message formatting and transfer requests. The message data is passed to the Presentation layer for encryption or formatting adjustments, then moves to the Session layer, which manages the communication session between the client and the email server.

At the Transport layer, TCP segments the email data, providing reliable delivery, and adds port information—commonly port 587 or 465 for SMTP with authentication. The Internet layer then encapsulates this into IP packets, assigning source and destination IP addresses, corresponding to the user’s device and the email server, respectively. The Data Link layer frames the packets for transmission over the local network, such as Ethernet, managing MAC addresses and access control. Finally, at the Physical layer, the bits are physically transmitted through the wired or wireless medium.

Upon reaching the email server, the reverse process occurs. The server processes the email data through the layers, verifies the sender, and routes the message toward the recipient’s email server, which then delivers it to the recipient’s mailbox. Consequently, the email arrives at the recipient’s Outlook application, where the process is effectively inverted to display the message to the user.

Conclusion

The layered architecture of network models like TCP/IP and OSI facilitates standardized, modular communication processes across diverse networks and systems. Understanding the mapping between TCP/IP and OSI, along with the responsibilities of standardization bodies, clarifies how data traverses network layers during common activities such as web browsing and email communication, ensuring interoperability and reliable data exchange across the internet.

References

  • Comer, D. E. (2018). Computer Networks and Internets (6th ed.). Pearson.
  • Forouzan, B. A. (2017). Data Communications and Networking (5th ed.). McGraw-Hill Education.
  • Kurose, J. F., & Ross, K. W. (2020). Computer Networking: A Top-Down Approach (7th ed.). Pearson.
  • Tanenbaum, A. S., & Wetherall, D. J. (2011). Computer Networks (5th ed.). Pearson.
  • ISO/IEC 7498-1:1994. Information technology — Open Systems Interconnection — Basic Reference Model: The Basic Model.
  • IEEE 802 Standards: Local Area Networks and Metropolitan Area Networks. IEEE Standards Association.
  • IETF RFC 791. (1981). Internet Protocol. https://tools.ietf.org/html/rfc791
  • IETF RFC 793. (1981). Transmission Control Protocol. https://tools.ietf.org/html/rfc793
  • ITU-T Recommendations. (2012). Overview of the OSI Reference Model. https://www.itu.int/en/ITU-T/publications/Pages/recommendations.aspx
  • Stewart, J. (2018). Internetworking with TCP/IP, Volume 1. Pearson.

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