Computer Networks · Unit 6 · 7 hrs
Application Layer
Exam-focused notes for Application Layer (Computer Networks, CSC263): what the TU syllabus asks and how it has actually been tested, with 6 solved past questions from this unit.
What this unit covers
- Introduction and Functions
- Web &HTTP
- DNS and the Query Types
- File Transfer and Email Protocols: FTP, SFTP, SMTP, IMAP, POP3
- Overview of Application Server Concepts: Proxy, Web, Mail
- Network Management: SNMP
DNS and the Query Types
What are the features of the application layer? Why is DNS required? Explain about recursive, non-recursive, and iterative DNS queries.[10]
--- The Application Layer is Layer 7 of the OSI model (also called the Desktop Layer). It is implemented by network applications that produce data to be transferred over the network. It serves as a window for application services to access the network and d...
Full solved answer →Why do we need a DNS system when we can directly use an IP address? what is domain name space? [5]
Although it is technically possible to access any resource on the internet using its IP address directly (e.g., typing 192.168.1.1 in a browser), the DNS system is needed for the following important reasons: - IP addresses are numeric (e.g., 142.250.190.46)...
Full solved answer →What do you understand by DNS? Explain FTP and SFTP. [5]
--- DNS is a hierarchical, distributed naming system used on the Internet that translates human-readable domain names (e.g., www.google.com) into machine-readable IP addresses (e.g., 142.250.64.100). - Without DNS, users would have to remember numeric IP ad...
Full solved answer →Overview of Application Server Concepts
Difference between web server and proxy server. [5]
A web server is a server that stores, processes, and delivers web content (HTML pages, images, files) directly to clients (browsers) using the HTTP protocol. It responds to client requests by serving the requested resources from its own storage. - It is the...
Full solved answer →File Transfer and Email Protocols
Differentiate between IMAP and POP3. Explain SNMP. [5]
--- Both IMAP and POP3 are email retrieval protocols used at the Application Layer to receive emails from a mail server. Feature IMAP (Internet Message Access Protocol) POP3 (Post Office Protocol v3) --------- Full Form Internet Message Access Protocol Post...
Full solved answer →Web &HTTP
Explain architecture of WWW. What is URL? [5]
The World Wide Web (WWW) is based on a Client/Server Architecture that operates over the Internet. It is a system of interlinked hypertext documents and resources accessed via the Internet using web browsers. - The client is the consumer side of the archite...
Full solved answer →Make Unit 6 stick
Practice CSC263 with flashcards & quizzes